WAL Western Alliance Bancorporation

As filed with the Securities and Exchange Commission on May 8, 2024

Registration No. 333-   

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

WESTERN ALLIANCE BANCORPORATION

(Exact name of registrant as specified in its charter)

One E. Washington Street, Suite 1400

Phoenix, Arizona 85004

Telephone: (602) 389-3500

(Address, including zip code, and telephone number, including area code, of registrants’ principal executive offices)

Dale M. Gibbons

Vice Chairman and Chief Financial Officer

Western Alliance Bancorporation

One E. Washington Street, Suite 1400

Phoenix, Arizona 85004

Telephone: (602) 389-3500

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Gregory F. Parisi, Esq.

Troutman Pepper Hamilton Sanders LLP

401 9th Street, N.W.

Washington, D.C. 20004

Telephone: (202) 274-2950

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the box. ☒

If this form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

PROSPECTUS

WESTERN ALLIANCE BANCORPORATION

Debt Securities

Common Stock

Preferred Stock

Depositary Shares

Purchase Contracts

Units

Warrants

By this prospectus, we or one or more selling securityholders to be identified in the future may offer the securities listed above in one or more offerings from time to time.

When we or any selling securityholder offers securities, we or they will provide you with a prospectus supplement describing the specific terms of the securities, including the price. You should read this prospectus and any prospectus supplement carefully before you decide to invest. This prospectus may not be used to sell securities unless it is accompanied by a prospectus supplement that further describes the securities being delivered to you.

We or any selling securityholder may offer and sell these securities to or through one or more underwriters, dealers and agents, or directly to purchasers, on a continuous or delayed basis.

Our common stock is listed for trading on the New York Stock Exchange under the symbol “WAL.” We have not yet determined whether any of the securities that may be offered by this prospectus will be listed on any exchange, or included in any inter-dealer quotation system or over-the-counter market. If we decide to seek the listing or inclusion of any such securities upon issuance, the prospectus supplement relating to those securities will disclose the exchange, quotation system or market on or in which the securities will be listed or included.

Investing in our securities involves risks. See “Risk Factors” in our most recent annual report on Form 10-K, which is incorporated herein by reference, and in any of our subsequently filed quarterly and current reports that are incorporated herein by reference. We may include specific risk factors in an applicable prospectus supplement under the heading “Risk Factors.”

The offered securities are not deposits or obligations of a bank or savings associations and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 8, 2024.

No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus or any accompanying prospectus supplement. You must not rely on any unauthorized information or representations. This prospectus and any prospectus supplement together are an offer to sell only the securities offered hereby and thereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained herein and in any accompanying prospectus supplement is current only as of its date.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration statement, we or a selling securityholder may sell, either separately or together, common stock, preferred stock, debt securities, depositary shares, purchase contracts, units and warrants.

Each time we or a selling securityholder sells securities, we or they will provide a prospectus supplement containing specific information about the terms of the securities being offered. The prospectus supplement may include a discussion of any risk factors or other special considerations that apply to those securities. The prospectus supplement may also add, update or change the information in this prospectus. If there is any inconsistency between the information in this prospectus (including the information incorporated by reference herein) and any prospectus supplement, you should rely on the information in the applicable prospectus supplement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

We are only responsible for the information contained in or incorporated by reference in this prospectus, any accompanying prospectus supplement or any related free writing prospectus. We have not authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus, in any accompanying prospectus supplement and in any related free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. You should not assume that the information contained in this prospectus or any prospectus supplement or in any such free writing prospectus is accurate as of any date other than their respective dates. In the case of information contained in documents we file with the SEC and incorporate by reference in this prospectus, you should assume that such information is accurate only as of the respective dates of those documents. Our business, financial condition, results of operations and prospects may have changed since those dates.

References in this prospectus to “Western Alliance,” “the Company,” “we,” “us” and “our” are to Western Alliance Bancorporation. In this prospectus, we sometimes refer to the debt securities, common stock, preferred stock, depository shares, purchase contracts, units, and warrants collectively as “offered securities.”

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act of 1933, as amended (the “Securities Act”), relating to the securities covered by this prospectus. This prospectus does not contain all the information set forth in the registration statement. For further information with respect to us and the securities offered by this prospectus, reference is made to the registration statement, including the exhibits to the registration statement and the documents incorporated by reference in the registration statement.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Because our common stock trades on the New York Stock Exchange under the symbol “WAL”, those materials can also be inspected and copied at the offices of that organization.

Whenever a document is summarized in this prospectus, that summary is qualified in its entirety by the actual document. You should refer to the exhibits that form a part of the registration statement for a copy of any such document.

Our filings, including the registration statement and the documents referred to below under “Incorporation of Certain Documents by Reference,” are available to the public at the SEC’s Internet website at http://www.sec.gov. Our SEC file number is 001-32550. Our SEC filings are also available at no cost on our website at https://investors.westernalliancebancorporation.com, as soon as reasonably practicable after we file such documents with the SEC.

You can also obtain any of the documents incorporated by reference from us, without charge (other than exhibits, unless the exhibits are specifically incorporated by reference), by requesting them in writing or by telephone at:

Western Alliance Bancorporation

One E. Washington Street, Suite 1400

Phoenix, Arizona 85004

(602) 389-3500

Attn: Dale M. Gibbons, Vice Chairman and Chief Financial Officer

THE INFORMATION ON OUR WEBSITE IS NOT A PROSPECTUS

AND IS NOT INCLUDED IN, NOR IS IT A PART OF,

THIS PROSPECTUS OR ANY PROSPECTUS SUPPLEMENT.

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” information into this prospectus. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be a part of this prospectus, except for any information that is superseded by other information that is included in or incorporated by reference into this document.

This prospectus incorporates by reference the documents listed below that we have previously filed with the SEC. These documents contain important information about us:

We also incorporate by reference any additional documents that we may file with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than those furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K or other information “furnished” to the SEC), from the date of the registration statement of which this prospectus is part until the termination of the offering of the offered securities. These documents may include annual, quarterly and current reports, as well as proxy statements. Any material that we later file with the SEC will automatically update and replace the information previously filed with the SEC. These documents are available to you without charge. See “Where You Can Find More Information.”

For purposes of this prospectus, any statement contained in a document incorporated or deemed to be incorporated herein by reference shall be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated herein by reference modifies or supersedes such statement in such document.

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NOTE REGARDING FORWARD-LOOKING STATEMENTS

Certain statements contained in this prospectus and the information included or incorporated by reference in it are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 (the “Reform Act”). Statements that constitute forward-looking statements within the meaning of the Reform Act are generally identified through the inclusion of words such as “aim,” “anticipate,” “believe,” “drive,” “estimate,” “expect,” “expressed confidence,” “forecast,” “future,” “goals,” “guidance,” “intend,” “may,” “opportunity,” “plan,” “position,” “potential,” “project,” “ seek,” “should,” “strategy,” “target,” “will,” “would” or similar statements or variations of such words and other similar expressions. All statements other than historical fact are “forward-looking statements” within the meaning of the Reform Act, including statements that are related to or are dependent on estimates or assumptions relating to expectations, beliefs, projections, future plans and strategies, anticipated events or trends and similar expressions that are not historical facts.

These forward-looking statements reflect our current views about future events and financial performance and involve certain risks, uncertainties, assumptions, and changes in circumstances that may cause our actual results to differ significantly from historical results and those expressed in any forward-looking statement. Factors that may cause actual results to differ materially from those contemplated by such forward-looking statements include, but are not limited to, those described in “Risk Factors” in Item 1A of our Annual Report on Form 10-K for the fiscal year ended December 31, 2023 and any report subsequently filed with the SEC. Forward-looking statements speak only as of the date they are made and we undertake no obligation to publicly update or revise any forward-looking statements included or incorporated by reference in this prospectus to update the reasons why actual results could differ from those contained in such statements, whether as a result of new information, future events or otherwise, except to the extent required by federal securities laws. In light of these risks, uncertainties and assumptions, the forward-looking events discussed in this prospectus might not occur, and you should not put undue reliance on any forward-looking statements.

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ABOUT WESTERN ALLIANCE BANCORPORATION

We are a bank holding company headquartered in Phoenix, Arizona, and incorporated under the laws of the state of Delaware. We provide a full spectrum of customized loan, deposit, and treasury management capabilities, including 24/7 funds transfer and other digital payment offerings through our wholly owned banking subsidiary, Western Alliance Bank (“WAB”).

WAB operates the following full-service banking divisions: Alliance Bank of Arizona, Bank of Nevada, First Independent Bank, Bridge Bank, and Torrey Pines Bank. We also provide an array of specialized financial services to business customers across the country, including mortgage banking services through AmeriHome and digital payment services for the class action legal industry. In addition, we have the following non-bank subsidiaries: CS Insurance Company, a captive insurance company formed and licensed under the laws of the State of Arizona and established as part of the Company’s overall enterprise risk management strategy, and Western Alliance Trust Company, which provides corporate trust services and levered loan administration solutions.

Our common stock is traded on the New York Stock Exchange under the ticker symbol “WAL.” Our principal executive offices are located at One E. Washington Street, Suite 1400, Phoenix, Arizona 85004. Our telephone number is (602) 389-3500. Our website is www.westernalliancebancorp.com. References to our website and those of our subsidiaries are not intended to be active links and the information on such websites is not, and you must not consider the information to be, a part of this prospectus.

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RISK FACTORS

We have included discussions of cautionary factors describing risks relating to our business and an investment in our securities in our Annual Report on Form 10-K for the year ended December 31, 2023 and our Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2024, as well as the risks, uncertainties and additional information set forth in the other documents incorporated by reference in this prospectus. For a description of these reports and documents, and information about where you can find them, see “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” Additional risks related to our securities may also be described in a prospectus supplement. Before purchasing our securities, you should carefully consider the risk factors we describe in any prospectus supplement or in any report incorporated by reference into this prospectus or such prospectus supplement. Although we discuss key risks in those risk factor descriptions, additional risks not currently known to us or that we currently deem immaterial also may impair our business. Our subsequent filings with the SEC may contain amended and updated discussions of significant risks. We cannot predict future risks or estimate the extent to which they may affect our financial performance.

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USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we expect to use the net proceeds from the sale of offered securities for general corporate purposes, including:

The prospectus supplement with respect to an offering of offered securities may identify different or additional uses for the proceeds of that offering. Except as otherwise stated in an applicable prospectus supplement, pending the application of the net proceeds, we expect to temporarily invest the proceeds from the sale of offered securities in short-term obligations. We will not receive proceeds from sales of securities by selling securityholders except as otherwise stated in an applicable prospectus supplement.

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THE SECURITIES WE MAY OFFER

The descriptions of the securities contained in this prospectus, together with the applicable prospectus supplements, summarize certain material terms and provisions of the various types of securities that we may offer. The particular material terms of the securities offered by a prospectus supplement will be described in that prospectus supplement. If indicated in the applicable prospectus supplement, the terms of the offered securities may differ from the terms summarized below. The prospectus supplement will also contain information, where applicable, about material U.S. federal income tax considerations relating to the offered securities, and the securities exchange, if any, on which the offered securities will be listed. The descriptions herein and in the applicable prospectus supplement do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of the actual documents whose terms are summarized herein and in the applicable prospectus supplement, because those documents, and not the summaries, define your rights as holders of the relevant securities. For more information, please review the forms of these documents, which are or will be filed with the SEC and will be available as described under the heading “Where You Can Find More Information” above.

We may offer and sell from time to time, in one or more offerings, the following:

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DESCRIPTION OF DEBT SECURITIES

General

We may issue senior debt securities and/or subordinated debt securities, which in each case will be unsecured, direct, general obligations of Western Alliance.

The senior debt securities will rank equally with all our other unsecured and unsubordinated debt. The subordinated debt securities will be subordinate and junior in priority of payment to our senior debt securities, as described below under “Ranking–Subordination of Subordinated Debt Securities” and in the prospectus supplement applicable to any subordinated debt securities that we may offer. For purposes of the descriptions in this section, we may refer to the senior debt securities and the subordinated debt securities collectively as the “debt securities.” The debt securities will be effectively subordinated to the creditors and preferred equity holders of our subsidiaries.

We will issue senior debt securities under a senior debt indenture and subordinated debt securities under a separate subordinated debt indenture. Provisions relating to the issuance of debt securities may also be set forth in a supplemental indenture to either of the indentures. For purposes of the descriptions in this section, we may refer to the senior debt indenture and the subordinated debt indenture and any related supplemental indentures, as “an indenture” or, collectively, as “the indentures.” The indentures will be qualified under and governed by the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

Each indenture will be between us and a trustee that meets the requirements of the Trust Indenture Act. We expect that each indenture will provide that there may be more than one trustee under that indenture, each with respect to one or more series of debt securities. Any trustee under an indenture may resign or be removed with respect to one or more series of debt securities and, in that event, we may appoint a successor trustee. Except as otherwise provided in the indenture or supplemental indenture, any action permitted to be taken by a trustee may be taken by that trustee only with respect to the one or more series of debt securities for which it is trustee under the applicable indenture.

The descriptions in this section relating to the debt securities and the indentures are summaries of their provisions. The summaries are not complete and are qualified in their entirety by reference to the actual indentures and debt securities and the further descriptions in the applicable prospectus supplement. A form of the senior debt indenture and a form of the subordinated debt indenture under which we may issue our senior debt securities and subordinated debt securities, respectively, and the forms of the debt securities, have been filed with the SEC as exhibits to the registration statement that includes this prospectus and will be available as described under the heading “Where You Can Find More Information” above. Whenever we refer in this prospectus or in any prospectus supplement to particular sections or defined terms of an indenture, those sections or defined terms are incorporated by reference in this prospectus or in the prospectus supplement, as applicable. You should refer to the provisions of the indentures for provisions that may be important to you.

The terms and conditions described in this section are terms and conditions that apply generally to the debt securities. The particular terms of any series of debt securities will be summarized in the applicable prospectus supplement. Those terms may differ from the terms summarized below.

Except as set forth in the applicable indenture or in a supplemental indenture and described in an applicable prospectus supplement, the indentures do not limit the amount of debt securities we may issue under the indentures. We are not required to issue all of the debt securities of one series at the same time and, unless otherwise provided in the applicable indenture or supplemental indenture and described in the applicable prospectus supplement, we may, from time to time, reopen any series and issue additional debt securities under that series without the consent of the holders of the outstanding debt securities of that series. Additional notes issued in this manner will have the same terms and conditions as the outstanding debt securities of that series, except for their original issue date and issue price, and will be consolidated with, and form a single series with, the previously outstanding debt securities of that series.

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Terms of Debt Securities to be Included in the Prospectus Supplement

The prospectus supplement relating to any series of debt securities that we may offer will set forth the price or prices at which the debt securities will be offered, and will contain the specific terms of the debt securities of that series. These terms may include, without limitation, the following:

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Unless otherwise specified in the applicable prospectus supplement, the debt securities will not be listed on any securities exchange.

We may offer and sell our debt securities at a substantial discount below their stated principal amount. These debt securities may be original issue discount securities, which means that less than the entire principal amount of the original issue discount securities will be payable upon declaration of acceleration of their maturity. Special federal income tax, accounting and other considerations applicable to original issue discount securities will be described in the applicable prospectus supplement.

We may issue debt securities with a fixed interest rate or a floating interest rate. Any material federal income tax considerations applicable to any discounted debt securities or to debt securities issued at par that are treated as having been issued at a discount for federal income tax purposes will be described in the applicable prospectus supplement.

Except as set forth in the applicable indenture or in a supplemental indenture, the debt securities will not contain any provisions that would limit our ability to incur indebtedness or that would afford holders of debt securities protection in the event of a highly leveraged or similar transaction involving us. The debt securities may contain provisions that would afford debt security holders protection in the event of a change of control. You should refer to the applicable prospectus supplement for information with respect to any deletions from, modifications of or additions to the events of default or covenants that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

For purposes of the descriptions in this section:

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Ranking

Senior Debt Securities

Payment of the principal of and premium, if any, and interest on debt securities we issue under the senior debt indenture will rank equally with all of our unsecured and unsubordinated debt.

Subordination of Subordinated Debt Securities

To the extent provided in the subordinated debt indenture and any supplemental indenture, and as described in the prospectus supplement describing the applicable series of subordinated debt securities, the payment of the principal of and premium, if any, and interest on any subordinated debt securities, including amounts payable on any redemption or repurchase, will be subordinated in right of payment and junior to senior debt, which is defined below. If there is a distribution to our creditors in a liquidation or dissolution of us, or in a bankruptcy, reorganization, insolvency, receivership or similar proceeding relating to us, the holders of senior debt will first be entitled to receive payment in full of all amounts due on the senior debt (or provision shall be made for such payment in cash) before any payments may be made on the subordinated debt securities. Because of this subordination, our general creditors may recover more, ratably, than holders of subordinated debt securities in the event of a distribution of assets upon insolvency.

The supplemental indenture will set forth the terms and conditions under which, if any, we will not be permitted to pay principal, premium, if any, or interest on the related subordinated debt securities upon the occurrence of an event of default or other circumstances arising under or with respect to senior debt.

The indentures will place no limitation on the amount of senior debt that we may incur. We expect to incur from time to time additional indebtedness constituting senior debt, which may include indebtedness that is senior to the subordinated debt securities but subordinate to our other obligations.

“Senior debt” means the principal of, and premium, if any, and interest, including interest accruing after the commencement of any bankruptcy proceeding relating to us, on, or substantially similar payments we will make in respect of the following categories of debt, whether that debt is outstanding at the date of execution of the applicable indenture or thereafter incurred, created or assumed:

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However, “senior debt” excludes:

As used above, the term “purchase money obligations” means indebtedness, obligations or guarantees evidenced by a note, debenture, bond or other instrument, whether or not secured by a lien or other security interest, and any deferred obligation for the payment of the purchase price of property but excluding indebtedness or obligations for which recourse is limited to the property purchased, issued or assumed as all or a part of the consideration for the acquisition of property or services, whether by purchase, merger, consolidation or otherwise, but does not include any trade accounts payable. There will not be any restrictions in the subordinated indenture relating to subordinated debt securities upon the creation of additional senior debt.

The applicable prospectus supplement may further describe the provisions, if any, applicable to the subordination of the subordinated debt securities of a particular series. The applicable prospectus supplement or the information incorporated by reference in the applicable prospectus supplement or in this prospectus will describe as of a recent date the approximate amount of our senior debt outstanding as to which the subordinated debt securities of that series will be subordinated.

Structural Subordination

Because we are a holding company, our cash flows and consequent ability to service our obligations, including our debt securities, are dependent on distributions and other payments of earnings and other funds by our subsidiaries to us. The payment of dividends and other distributions by our subsidiaries is contingent on their earnings and is subject to the requirements of federal banking regulations and other restrictions. In addition, the debt securities will be structurally subordinated to all indebtedness and other liabilities of our subsidiaries, since our right to receive any assets of its subsidiaries upon their liquidation or reorganization, and the consequent right of the holders of the debt securities to participate in those assets, will be effectively subordinated to the claims of that subsidiary’s creditors. If we are recognized as a creditor of that subsidiary, our claims would still be subordinate to any security interest in the assets of that subsidiary and any indebtedness of that subsidiary senior to that held by us. Claims from creditors (other than us), on subsidiaries may include long-term and medium-term debt and substantial obligations related to deposit liabilities, federal funds purchased, securities sold under repurchase agreements and other short-term borrowings. Any capital loans that we make to our non-banking subsidiaries would be subordinate in right of payment to deposits and to other indebtedness of WAB or our non-banking subsidiaries.

Conversion or Exchange of Debt Securities

The applicable prospectus supplement will set forth the terms, if any, on which a series of debt securities may be converted into or exchanged for our other securities. These terms will include whether conversion or exchange is mandatory, or is at our option or at the option of the holder. We will also describe in the applicable prospectus supplement how we will calculate the number of securities that holders of debt securities would receive if they were to convert or exchange their debt securities, the conversion price and other terms related to conversion and any anti-dilution protections.

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Redemption of Securities

We may redeem the debt securities at any time, in whole or in part, at the prescribed redemption price, at the times and on the terms described in the applicable prospectus supplement.

From and after notice has been given as provided in the indentures, if we have made available funds for the redemption of any debt securities called for redemption on the applicable redemption date, the debt securities will cease to bear interest on the date fixed for the redemption specified in the notice, and the only right of the holders of the debt securities will be to receive payment of the redemption price.

Notice of any optional redemption by us of any debt securities is required to be given to holders at their addresses, as shown in the security register. The notice of redemption will be required to specify, among other items, the redemption price and the principal amount of the debt securities held by the holder to be redeemed.

If we elect to redeem debt securities, we will be required to notify the trustee of the aggregate principal amount of debt securities to be redeemed and the redemption date. If fewer than all the debt securities are to be redeemed, the trustee is required to select the debt securities to be redeemed equally, by lot or in a manner it deems fair and appropriate.

Denomination, Interest, Registration and Transfer

Unless otherwise specified in the applicable prospectus supplement, we will issue the debt securities (i) in denominations of $1,000 or integral multiples of $1,000 if the debt securities are in registered form, and (ii) in denominations of $5,000 if the debt securities are in bearer form.

Unless otherwise specified in the applicable prospectus supplement, we will pay the principal of, and applicable premium, if any, and interest on any series of debt securities at the corporate trust office of the trustee, the address of which will be stated in the applicable prospectus supplement. At our option, we may pay interest by check mailed to the address of the person entitled to the interest payment as it appears in the register for the applicable debt securities or by wire transfer of funds to that person at an account maintained within the United States.

Any defaulted interest, which means interest not punctually paid or duly provided for on any interest payment date with respect to a debt security, will immediately cease to be payable to the registered holder on the applicable regular record date by virtue of his having been the registered holder on such date. We may pay defaulted interest either to the person in whose name the debt security is registered at the close of business on a special record date for the payment of the defaulted interest to be fixed by the trustee, notice of which is to be given to the holder of the debt security not less than ten days before the special record date, or at any time in any other lawful manner, all as more completely described in the applicable indenture or supplemental indenture.

Subject to limitations imposed upon debt securities issued in book-entry form, the holder may exchange debt securities of any series for other debt securities of the same series and of a like aggregate principal amount and tenor of different authorized denominations upon surrender of the debt securities at the corporate trust office of the applicable trustee. In addition, subject to limitations imposed upon debt securities issued in book-entry form, the holder may surrender debt securities of any series for registration of transfer or exchange at the corporate trust office of the applicable trustee. Every debt security surrendered for registration of transfer or exchange must be duly endorsed or accompanied by a written instrument of transfer. No service charge will be imposed for any registration of transfer or exchange of any debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with any registration of transfer or exchange of any debt securities. If the applicable prospectus supplement refers to any transfer agent, in addition to the applicable trustee, initially designated by us with respect to any series of debt securities, we may at any time rescind the designation of that transfer agent or approve a change in the location through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for that series. We may at any time designate additional transfer agents with respect to any series of debt securities.

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If we redeem the debt securities of any series, neither we nor any trustee will be required to:

Global Securities

We may issue the debt securities of a series in whole or in part in the form of one or more global securities to be deposited with, or on behalf of, a depository or with a nominee for a depository identified in the applicable prospectus supplement relating to that series. We may issue global securities in either registered or bearer form and in either temporary or permanent form. The specific terms of the depository arrangement with respect to a series of debt securities will be described in the prospectus supplement relating to that series.

Our obligations with respect to the debt securities, as well as the obligations of the applicable trustee, run only to persons who are registered holders of debt securities. For example, once we make payment to the registered holder, we have no further responsibility for that payment even if the recipient is legally required to pass the payment along to an individual investor but fails to do so. As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to transfers of debt securities.

An investor should be aware that when debt securities are issued in the form of global securities:

The applicable prospectus supplement for a series of debt securities will list the special situations, if any, in which a global security will terminate and interests in the global security will be exchanged for physical certificates representing debt securities. After that exchange, the investor may choose whether to hold debt securities directly or indirectly through an account at the investor’s bank or brokerage firm. In that event, investors must consult their banks or brokers to find out how to have their interests in debt securities transferred to their own names so that they may become direct holders. When a global security terminates, the depositary, and not us or one of the trustees, is responsible for deciding the names of the institutions that will be the initial direct holders.

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Merger, Consolidation or Sale of Assets

We will not be permitted to consolidate with or merge into any other entity, or sell, lease, transfer or convey all or substantially all of our properties and assets, either in one transaction or a series of transactions, to any other entity and no other entity will consolidate with or merge into us, or sell, lease, transfer or convey all or substantially all of its properties and assets to us unless:

Except as provided in this prospectus or as may otherwise be provided in the applicable prospectus supplement, the indenture and the terms of the debt securities will not contain any event risks or similar covenants that are intended to afford protection to holders of any debt securities in the event of a merger, a highly leveraged transaction or other significant corporate event involving us or our subsidiaries, whether or not resulting in a change of control, which may adversely affect holders of the debt securities.

Additional Covenants and/or Modifications to the Covenant Described Above

Any additional covenants and/or modifications to the covenants described above with respect to any series of debt securities, including any covenants relating to limitations on incurrence of indebtedness or other financial covenants, will be set forth in the applicable indenture or supplemental indenture and described in the applicable prospectus supplement relating to that series of debt securities.

Unless the applicable prospectus supplement indicates otherwise, the subordinated debt indenture does not contain any other provision which restricts us from, among other things:

Events of Default, Waiver and Notice

Events of Default

The events of default with respect to any series of debt securities issued under it, subject to any modifications or deletions provided in any supplemental indenture with respect to any specific series of debt securities, include the following events:

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If an event of default under any indenture with respect to debt securities of any series at the time outstanding occurs and is continuing, then in every case other than in the case of specific events of bankruptcy, insolvency or reorganization, or court appointment of a receiver, liquidator or trustee of us or any significant subsidiary or either of our property, in which case acceleration will be automatic, the applicable trustee or the holders of not less than 25% of the principal amount of the outstanding debt securities of that series will have the right to declare the principal amount, or, if the debt securities of that series are original issue discount securities or indexed securities, the portion of the principal amount as may be specified in the terms of that series, of all the debt securities of that series to be due and payable immediately by written notice to us, and to the applicable trustee if given by the holders. At any time after a declaration of acceleration has been made with respect to debt securities of a series, or of all debt securities then outstanding under any indenture, as the case may be, but before a judgment or decree for payment of the money due has been obtained by the applicable trustee, however, the holders of not less than a majority in principal amount of the outstanding debt securities of that series, or of all debt securities then outstanding under the applicable indenture, as the case may be, may annul the declaration of acceleration and waive any default in respect of those debt securities if:

Waiver

Each indenture also will provide that the holders of not less than a majority in principal amount of the outstanding debt securities of any series, or of all debt securities then outstanding under the applicable indenture, as the case may be, may waive any past default with respect to that series and its consequences, except a default:

Notice

Each trustee will be required to give notice to the holders of the applicable debt securities within 90 days of a default under the applicable indenture unless the default has been cured or waived; but the trustee may withhold notice of any default, except a default in the payment of the principal of, or premium, if any, or interest on the

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debt securities or in the payment of any sinking fund installment in respect of the debt securities, if specified responsible officers of the trustee consider the withholding to be in the interest of the holders.

The holders of debt securities of any series may not institute any proceedings, judicial or otherwise, with respect to the indentures or for any remedy under the indentures, except in the case of failure of the applicable trustee, for 60 days, to act after the trustee has received a written request to institute proceedings in respect of an event of default from the holders of not less than 25% in principal amount of the outstanding debt securities of that series, as well as an offer of indemnity reasonably satisfactory to the trustee, and provided that no direction inconsistent with such written request has been given to the trustee during such 60-day period by the holders of a majority of the outstanding debt securities of that series. However, any holder of debt securities is not prohibited from instituting suit for the enforcement of payment of the principal of, and premium, if any, and interest on the debt securities at their respective due dates.

Subject to the trustee’s duties in case of default, no trustee will be under any obligation to exercise any of its rights or powers under an indenture at the request or direction of any holders of any series of debt securities then outstanding under that indenture, unless the holders offer to the trustee reasonable security or indemnity. Subject to such provisions for the indemnification of the trustee, the holders of not less than a majority in principal amount of the outstanding debt securities of any series, or of all debt securities then outstanding under an indenture, as the case may be, will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the applicable trustee, or of exercising any trust or power conferred upon the trustee. A trustee may refuse, however, to follow any direction that is in conflict with any law or the applicable indenture that may involve the trustee in personal liability or may be unduly prejudicial to the holders of debt securities of that series not joining in the direction.

Within 180 days after the end of each fiscal year, we will be required to deliver to each trustee a certificate, signed by one of several specified officers, stating whether or not that officer has knowledge of any default under the applicable indenture and, if so, specifying each default and the nature and status of the default.

Modification of the Indentures

Except as otherwise specifically provided in the applicable indenture, with the consent of the holders of not less than a majority in principal amount of all outstanding debt securities issued under that indenture that are affected by the modification or amendment, we may enter into supplemental indentures with the trustee for the purpose of adding any provisions to or changing in any manner or eliminating any of the provisions of such indenture or of modifying in any manner the rights of the holders under debt securities issued under such indenture. However, no modification or amendment may, without the consent of the holder of each debt security affected by the modification or amendment:

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The holders of not less than a majority in principal amount of the outstanding debt securities of each series affected by the modification or amendment will have the right to waive compliance by us with specific covenants in the indenture.

We and the respective trustee may modify and amend an indenture without the consent of any holder of debt securities for any of the following purposes:

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In determining whether the holders of the requisite principal amount of outstanding debt securities of a series have given any request, demand, authorization, direction, notice, consent or waiver under the indenture or whether a quorum is present at a meeting of holders of debt securities:

Discharge, Defeasance and Covenant Defeasance

Discharge

We may be permitted under the applicable indenture to discharge specific obligations to holders of any series of debt securities (1) that have not already been delivered to the applicable trustee for cancellation and (2) that either have become due and payable or will, within one year, become due and payable or scheduled for redemption, by irrevocably depositing with the applicable trustee, in trust, money or funds certified to be sufficient to pay when due, whether at maturity, upon redemption or otherwise, the principal of, and premium, if any, on and interest on the debt securities.

Defeasance and Covenant Defeasance

If the provisions of the applicable indenture relating to defeasance and covenant defeasance are made applicable to the debt securities of or within any series, we may elect either:

in either case upon the irrevocable deposit by us with the applicable trustee, in trust, of an amount, in currency or currencies or government obligations, or both, sufficient without reinvestment to make scheduled payments of the principal of, and premium, if any, and interest on the debt securities, when due, whether at maturity, upon redemption or otherwise, and any mandatory sinking fund or analogous payments.

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A trust will only be permitted to be established if, among other things:

In general, if we elect covenant defeasance with respect to any debt securities and payments on those debt securities are declared due and payable because of the occurrence of an event of default, the amount of money and/or government obligations on deposit with the applicable trustee would be sufficient to pay amounts due on those debt securities at the time of their stated maturity, but may not be sufficient to pay amounts due on those debt securities at the time of the acceleration resulting from the event of default. In that case, we would remain liable to make payment of the amounts due on the debt securities at the time of acceleration.

The applicable prospectus supplement may further describe the provisions, if any, permitting defeasance or covenant defeasance, including any modifications to the provisions described above, with respect to the debt securities of or within a particular series

Regarding the Trustees

We will designate the trustee under the senior and subordinated debt indentures in the applicable prospectus supplement. From time to time, we may enter into banking or other relationships with any of such trustees or their affiliates.

There may be more than one trustee under each indenture, each with respect to one or more series of debt securities. Any trustee may resign or be removed with respect to one or more series of debt securities, and a successor trustee may be appointed to act with respect to such series.

If two or more persons are acting as trustee with respect to different series of debt securities, each trustee will be a trustee of a trust under the indenture separate from the trust administered by any other such trustee. Except as otherwise indicated in this prospectus, any action to be taken by the trustee may be taken by each such trustee with respect to, and only with respect to, the one or more series of debt securities for which it is trustee under the indenture.

Governing Law

The senior debt securities, the subordinated debt securities and the related indentures will be governed by, and construed in accordance with, the internal laws of the State of New York.

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DESCRIPTION OF COMMON STOCK

The following description is a general summary of the terms of our common stock. The description below does not purport to be complete and is subject to and qualified in its entirety by reference to our certificate of incorporation and bylaws. The description herein does not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of our certificate of incorporation, bylaws, and the applicable provisions of the Delaware General Corporation Law (the “DGCL” or “Delaware Law”) because they, and not the summary, define the rights of holders of shares of our common stock.

General

Our certificate of incorporation provides the authority to issue 200,000,000 shares of common stock, par value $0.0001 per share. Each share of our common stock has the same relative rights and is identical in all respects to each other share of our common stock. Our common stock is non-withdrawable capital, is not of an insurable type and is not insured by the Federal Deposit Insurance Corporation or any other governmental entity. On March 31, 2024, there were 113,005,772 shares of common stock issued and we had outstanding stock options granted to directors, officers and other employees for 1,705 shares of our common stock. Also on March 31, 2024, we had no issued and outstanding warrants to purchase shares of our common stock.

Voting Rights

Holders of our common stock are entitled to one vote per share on each matter properly submitted to stockholders for their vote, including the election of directors. Holders of our common stock do not have the right to cumulate their votes for the election of directors, which means that the holders of more than 50% of the shares of common stock voting for the election of directors can elect 100% of the directors standing for election at any meeting if they choose to do so. In that event, the holders of the remaining shares voting for the election of directors will not be able to elect any person or persons to our board of directors at that meeting. Generally, in matters other than the election of directors and business combinations and other extraordinary transactions, the affirmative vote of the majority of shares present and entitled to vote on the subject matter constitutes the act of the stockholders. A nominee to our board of directors will be elected, in uncontested elections (as defined in our bylaws), if the votes cast for such nominee’s election exceed the votes cast against such nominee’s election. In all director elections other than uncontested elections, the vote standard will continue to be a plurality of votes cast, and stockholders shall not be permitted to vote against any nominee for director.

Liquidation Rights

The holders of our common stock and the holders of any class or series of stock entitled to participate with the holders of our common stock as to the distribution of assets in the event of any liquidation, dissolution or winding-up of us, whether voluntary or involuntary, will become entitled to participate equally in the distribution of any of our assets remaining after we have paid, or provided for the payment of, all of our debts and liabilities and after we have paid, or set aside for payment, to the holders of any class of stock having preference over the common stock in the event of liquidation, dissolution or winding-up, the full preferential amounts, if any, to which they are entitled.

Dividends

The holders of our common stock and any class or series of stock entitled to participate with the holders of our common stock are entitled to receive dividends declared by our board of directors out of any assets legally available for distribution. The board may declare dividends out of surplus, or if no surplus exists, out of net profits for the fiscal year in which the dividend is declared and/or the preceding fiscal year, only if the amount of capital is greater than or equal to the aggregate amount of the capital represented by the issued and outstanding stock of all classes having a preference upon the distribution of assets. The terms and conditions of other

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securities we issue may restrict our ability to pay dividends to holders of our common stock. In addition, as a holding company, our main source of funds to pay dividends is distributions from our subsidiaries and, therefore, our ability to pay distributions is affected by the ability of our subsidiaries to pay dividends. The ability of our bank subsidiary, and our ability, to pay dividends in the future is, and could in the future be further, influenced by bank regulatory requirements and capital guidelines.

Miscellaneous

The holders of our common stock have no preemptive or conversion rights for any shares that may be issued. Our common stock is not subject to additional calls or assessments, and all shares of our common stock currently outstanding are fully paid and non-assessable.

Anti-Takeover Effects of Provisions of our Certificate of Incorporation and Bylaws and Delaware Law

Some provisions of Delaware Law and our certificate of incorporation and bylaws contain provisions that could make it more difficult to (1) acquire us by means of a tender offer, proxy contest or otherwise or (2) remove our incumbent officers and directors. These provisions, summarized below, are intended to encourage persons seeking to acquire control of us to first negotiate with our board of directors. These provisions also serve to discourage hostile takeover practices and inadequate takeover bids.

Undesignated Preferred Stock

Our board of directors has the ability to authorize undesignated preferred stock, which allows the board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any unsolicited attempt to change control of our company. This ability may have the effect of deferring hostile takeovers or delaying changes in control or management of our company.

Special Stockholders’ Meetings and Advanced Notice Requirements for Stockholder Proposals

Our certificate of incorporation and bylaws provide that a special meeting of stockholders may be called only by our board of directors, the chairman of the board, or by our chief executive officer or president. In addition, our bylaws require advance notice procedures for stockholder proposals to be brought before an annual meeting of the stockholders, including the nomination of directors. Stockholders at an annual meeting may only consider the proposals specified in the notice of meeting or brought before the meeting by or at the direction of the board, or by a stockholder of record on the record date for the meeting who (1) is entitled to vote at the meeting, (2) has delivered a timely written notice in proper form to our secretary of the stockholder’s intention to bring such business before the meeting, (3) attends (or has a qualified representative attend) the stockholder meeting and (4) has otherwise complied with the provisions of our bylaws and applicable law. These provisions could have the effect of delaying any stockholder actions until the next stockholder meeting, even if they are favored by the holders of a majority of our outstanding voting stock.

No Action by Written Consent

Our certificate of incorporation and bylaws do not permit stockholders to act by written consent in lieu of a meeting.

Election and Removal of Directors

Our certificate of incorporation provides for the annual election of directors. Once elected, directors may be removed by the holders of a majority of shares then entitled to vote in an election of directors. In addition, our certificate of incorporation and bylaws provide that any vacancies on the board of directors may be filled only by a majority of the remaining directors.

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Amendment of Certain Provisions of our Organizational Documents

Any amendment to our certificate of incorporation must be approved by our board of directors and a majority of the outstanding shares of each class of shares entitled to vote thereon at a duly called annual or special meeting; provided, that in addition to any vote of any class of shares required by law or the certificate of incorporation, the affirmative vote of holders of at least a majority of the voting power of all of the then outstanding shares of our capital stock entitled to vote generally in the election of directors, voting together as a single class, is required to amend certain of the provisions contained in the certificate of incorporation regarding stockholder actions, classification of directors, removal of directors, filling of director vacancies, bylaw amendments, limitation of liability of directors, the exclusive forum for certain litigation, and amendments to the certificate of incorporation. Our bylaws may be amended by the affirmative vote of a majority of the directors present at a meeting at which a quorum is present or by the affirmative vote of the holders of at least 66-2/3% of the voting power of all of the shares of capital stock issued and outstanding and entitled to vote in any election of directors, voting as a single class.

Business Combinations

We have not opted out of Section 203 of the DGCL, an anti-takeover law, and are therefore subject to its provisions. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a business combination, such as a merger, with a person or group owning 15% or more of the corporation’s outstanding voting stock, referred to as an “interested stockholder” under Section 203, for a period of three years following the date the person became an interested stockholder, unless (with certain exceptions) the business combination or the transaction in which the person became an interested stockholder is approved in a prescribed manner.

These and other provisions of Delaware Law and our certificate of incorporation and bylaws could have the effect of discouraging others from attempting hostile takeovers or delaying changes in control and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. Such provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish transactions which shareholders may otherwise deem to be in their best interests.

NYSE Listing

Our common stock is listed on the New York Stock Exchange under the symbol “WAL.”

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A., PO Box 505000, Louisville, Kentucky 40233.

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DESCRIPTION OF PREFERRED STOCK

The following description is a general summary of the terms of the preferred stock which we may issue. The description below and in any prospectus supplement does not purport to be complete and is subject to and qualified in its entirety by reference to our certificate of incorporation, and the applicable certificate of designation to our certificate of incorporation, determining the terms of the related series of preferred stock and our bylaws, each of which we will make available upon request. The descriptions herein and in the applicable prospectus supplement do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of our certificate of incorporation, the applicable certificate of designation and our bylaws because they, and not the summaries, define your rights as holders of shares of our preferred stock.

General

We are authorized to issue 20,000,000 shares of preferred stock, par value $0.0001 per share. As of March 31, 2024, there were 30,000 shares of preferred stock issued and outstanding. Our certificate of incorporation, subject to limitations prescribed in such certificate and subject to limitations prescribed by Delaware law, authorizes the board of directors, from time to time by resolution and without further stockholder action, to provide for the issuance of shares of preferred stock, in one or more series, and to fix the designation, powers, preferences and other rights of the shares and to fix the qualifications, limitations and restrictions thereof. As a result of its broad discretion with respect to the creation and issuance of preferred stock without stockholder approval, the board of directors could adversely affect the voting power of the holders of common stock and, by issuing shares of preferred stock with certain voting, conversion and/or redemption rights, could discourage any attempt to obtain control of us.

Terms of the Preferred Stock That We May Offer and Sell to You

You should refer to the prospectus supplement relating to the class or series of preferred stock for the specific terms of that class or series, including:

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Ranking

Unless otherwise specified in the applicable prospectus supplement, the preferred stock will, with respect to distribution rights and rights upon liquidation, dissolution or winding up of our affairs, rank:

For purposes of this subheading, the term “equity securities” does not include convertible debt securities.

Distributions

Holders of the preferred stock of each series will be entitled to receive, when, as and if declared by our board of directors, out of our assets legally available for payment to stockholders, cash distributions, or distributions in kind or in other property if expressly permitted and described in the applicable prospectus supplement, at the rates and on the dates as we will set forth in the applicable prospectus supplement. We will pay each distribution to holders of record as they appear on our stock transfer books on the record dates determined by our board of directors.

Distributions on any class or series of preferred stock, if cumulative, will be cumulative from and after the date set forth in the applicable prospectus supplement. If our board of directors fails to declare a distribution payable on a distribution payment date on any class or series of preferred stock for which distributions are non-cumulative, then the holders of that class or series of preferred stock will have no right to receive a distribution in respect of the distribution period ending on that distribution payment date, and we will have no obligation to pay the distribution accumulated for that period, whether or not distributions on that series are declared payable on any future distribution payment date.

If any shares of the preferred stock of any class or series are outstanding, no full dividends will be declared or paid or set apart for payment on our preferred stock of any other class or series ranking, as to dividends, equally with or junior to the preferred stock of the class or series for any period unless all required dividends are paid. The phrase “all required dividends are paid” when used in this prospectus with respect to class or series of preferred stock means that:

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When dividends are not paid in full, or a sum sufficient for the full payment is not so set apart, upon the shares of preferred stock of any class or series and the shares of any other class or series of preferred stock ranking equally as to dividends with the preferred stock of the class or series, all dividends declared upon shares of preferred stock of the class or series and any other class or series of preferred stock ranking equally as to dividends with the preferred stock will be declared equally so that the amount of dividends declared per share on the preferred stock of the class or series and the other class or series of preferred stock will in all cases bear to each other the same ratio that accrued and unpaid dividends per share on the shares of preferred stock of the class or series, which will not include any accumulation in respect of unpaid dividends for prior dividend periods if the preferred stock does not have cumulative dividend, and the other class or series of preferred stock bear to each other. No interest, sum of money in lieu of interest, will be payable in respect of any dividend payment or payments on preferred stock of the class or series which may be in arrears.

Except as provided in the immediately preceding paragraph, unless all required dividends are paid, no dividends, other than in common stock or other stock ranking junior to the preferred stock of the class or series as to dividends and upon liquidation, dissolution or winding-up of us, will be declared or paid or set aside for payment or other distribution will be declared or made upon the common stock or any of our other stock ranking junior or equally with the preferred stock of the class or series as to dividends or upon liquidation, nor will any common stock or any of our other capital stock ranking junior to or equally with preferred stock of the class or series as to dividends or upon liquidation, dissolution or winding-up of us be redeemed, purchased or otherwise acquired for any consideration, or any moneys be paid to or made available for a sinking fund for the redemption of any shares of any stock, by us except by conversion into or exchange for our other stock ranking junior to the preferred stock of the class or series as to dividends and upon liquidation, dissolution or winding-up of us.

Any dividend payment made on shares of a class or series of preferred stock will first be credited against the earliest accrued but unpaid dividend due with respect to shares of the class or series which remains payable.

Redemption

If so provided in the applicable prospectus supplement, the preferred stock will be subject to mandatory redemption or redemption at our option, in whole or in part, in each case upon the terms, at the times and at the redemption prices set forth in such prospectus supplement.

Liquidation Preference

Upon any voluntary or involuntary liquidation, dissolution or winding up of our affairs, then, before any distribution or payment will be made to the holders of any common stock or any other class or series of shares of our capital stock ranking junior to the preferred stock in the distribution of assets upon any liquidation, dissolution or winding up of our affairs, the holders of each series or class of preferred stock will be entitled to receive out of our assets legally available for distribution to stockholders liquidating distributions in the amount of the liquidation preference set forth in the applicable prospectus supplement, plus an amount equal to all accumulated and unpaid distributions. If, upon the voluntary or involuntary liquidation, dissolution or winding up, our available assets are insufficient to pay the amount of the liquidating distributions on all outstanding shares of preferred stock and the corresponding amounts payable on all shares of other classes or series of shares of our capital stock ranking equally with the preferred stock in the distribution of assets, then the holders of the preferred stock and all other classes or series of shares of capital stock will share ratably in any distribution of assets in proportion to the full liquidating distributions to which they would otherwise be respectively entitled.

If liquidating distributions will have been made in full to all holders of preferred stock, our remaining assets will be distributed among the holders of any other classes or series of shares of capital stock ranking junior to the

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preferred stock upon liquidation, dissolution or winding up, according to their respective rights and preferences and in each case according to their respective number of shares.

For those purposes, the consolidation or merger of us with or into any other corporation, trust or entity, or the sale, lease or conveyance of all or substantially all of our property or business, will not be deemed to constitute a liquidation, dissolution or winding up of our affairs.

Voting Rights

Holders of preferred stock will not have any voting rights, except as set forth below or as otherwise from time to time required by law, or as otherwise provided in the certificate of designation or the resolutions establishing such series and as indicated in the applicable prospectus supplement.

Under the Delaware General Corporation Law, holders of outstanding shares of a series of preferred stock may be entitled to vote as a separate class on a proposed amendment to the terms of that series of preferred stock or our certificate of incorporation, if the amendment would:

Conversion Rights

The terms and conditions, if any, upon which any class or series of preferred stock are convertible into or exchangeable for our other securities or rights or those of other issuers, including, without limitation, common stock, debt securities or preferred stock, or any combination of the foregoing, will be set forth in the applicable prospectus supplement relating to the preferred stock. The terms will include the name of the issuer of the other securities or rights and the number or principal amount of the securities or rights into which the shares of preferred stock are convertible or exchangeable, the conversion or exchange price or rate or the manner of calculating the price, the conversion or exchange date(s) or period(s), provisions as to whether conversion or exchange will be at the option of the holders of the preferred stock or at our or other issuer’s option, the events requiring an adjustment of the conversion or exchange price or rate and provisions affecting conversion or exchange in the event of the redemption of the series of preferred stock.

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DESCRIPTION OF DEPOSITARY SHARES

The following description, together with the applicable prospectus supplements, summarizes certain terms and provisions of the depositary shares that we may offer under this prospectus and the related deposit agreements and depositary receipts. The following summary relates to terms and conditions applicable to these types of securities generally. The particular terms of any series of depositary shares will be those set forth in the applicable deposit agreement and summarized in the applicable prospectus supplement. If indicated in the applicable prospectus supplement, the terms of any series may differ from the terms summarized below.

Specific deposit agreements and depositary receipts will contain additional important terms and provisions and will be incorporated by reference into the registration statement which includes this prospectus before we issue any depositary shares. The descriptions herein and in the applicable prospectus supplement do not restate those agreements and receipts in their entirety and do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of the applicable deposit agreement and deposit certificate because they, and not the summaries, define your rights as holders of the depositary shares. For more information, please review the forms of these documents, which will be filed with the SEC will be available as described under the heading “Where You Can Find More Information” above.

General

We may elect to offer fractional shares of preferred stock rather than full shares of preferred stock. If so, we will issue “depositary receipts” for these “depositary shares.” Each depositary share will represent a fraction of a share of a particular series of preferred stock. Each holder of a depositary share will be entitled, in proportion to the fraction of preferred stock represented by that depositary share, to the rights and preferences of the preferred stock, including dividend, voting, redemption, conversion and liquidation rights, if any. We will enter into a deposit agreement with a depositary, which will be named in the applicable prospectus supplement.

In order to issue depositary shares, we will issue preferred stock and immediately deposit these shares with the depositary. The depositary will then issue and deliver depositary receipts to the persons who purchase depositary shares. Each whole depositary share issued by the depositary may represent a fraction of a share held by the depositary. The depositary will issue depositary receipts in a form that reflects whole depositary shares, and each depositary receipt may evidence any number of whole depositary shares.

Pending the preparation of definitive engraved depositary receipts, a depositary may, upon our written order, issue temporary depositary receipts, which will temporarily entitle the holders to all the rights pertaining to the definitive depositary receipts. We will bear the costs and expenses of promptly preparing definitive depositary receipts and of exchanging the temporary depositary receipts for definitive depositary receipts.

Dividends and Other Distributions

The depositary will distribute all cash and non-cash dividends and distributions it receives with respect to the underlying preferred stock to the record holders of depositary shares in proportion to the number of depositary shares they hold. In the case of non-cash distributions, the depositary may determine that it is not feasible to make the distribution. If so, the depositary may, with our approval, sell the property and distribute the net proceeds from the sale to the holders. The amounts distributed by the depositary will be reduced by any amount required to be withheld by us or the depositary on account of taxes.

Redemption of Depositary Shares

If we redeem the series of preferred stock that underlies the depositary shares, the depositary will redeem the depositary shares from the proceeds it receives from the redemption of the preferred stock it holds. The depositary will redeem the number of depositary shares that represent the amount of underlying preferred stock

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that we have redeemed. The redemption price for depositary shares will be in proportion to the redemption price per share that we paid for the underlying preferred stock. If we redeem less than all of the depositary shares, the depositary will select which depositary shares to redeem by lot, or some substantially equivalent method.

After a redemption date is fixed, the depositary shares to be redeemed no longer will be considered outstanding. The rights of the holders of the depositary shares will cease, except for the rights to receive money or other property upon redemption. In order to redeem their depositary shares, holders will surrender their depositary receipts to the depositary.

Voting the Preferred Stock

We will notify the depositary about any meeting at which the holders of preferred stock are entitled to vote, and the depositary will mail the information to the record holders of depositary shares related to that preferred stock. Each record holder of depositary shares on the record date will be entitled to instruct the depositary on how to vote the shares of preferred stock represented by that holder’s depositary shares. The depositary will vote the preferred stock represented by the depositary shares in accordance with these instructions, provided the depositary receives these instructions sufficiently in advance of the meeting. If the depositary does not receive instructions from the holders of the depositary shares, the depositary will abstain from voting the preferred stock that underlies those depositary shares.

Withdrawal of Preferred Stock

When a holder surrenders depositary receipts at the corporate trust office of the depositary, and pays any necessary taxes, charges or other fees, the holder will be entitled to receive the number of whole shares of the related series of preferred stock, and any money or other property, if any, represented by the holder’s depositary shares. Once a holder exchanges depositary shares for whole shares of preferred stock, that holder cannot “re-deposit” these shares of preferred stock with the depositary, or exchange them for depositary shares. If a holder delivers depositary receipts that represent a number of depositary shares that exceeds the number of whole shares of related preferred stock the holder seeks to withdraw, the depositary will issue a new depositary receipt to the holder that evidences the excess number of depositary shares.

Amendment and Termination of the Deposit Agreement

We and the depositary can agree, at any time, to amend the form of depositary receipt and any provisions of the depositary receipt and any provisions of the deposit agreement. However, if an amendment has a material adverse effect on the rights of the holders of related depositary shares, the holders of at least a majority of the depositary shares then outstanding must first approve the amendment. Every holder of a depositary receipt at the time an amendment becomes effective will be bound by the amended deposit agreement. However, subject to any conditions in the deposit agreement or applicable law, no amendment can impair the right of any holder of a depositary share to receive shares of the related preferred stock, or any money or other property represented by the depositary shares, when they surrender their depositary receipts.

We can terminate the deposit agreement at any time, as long as the depositary mails notice of termination to the record holders of depositary shares then outstanding at least 30 days prior to the date fixed for termination. Upon termination, the depositary shall deliver to each holder of depositary receipts, upon surrender of the depositary receipts held by such holder, such number of whole or fractional shares of preferred stock as are represented by the depositary shares evidenced by such depositary receipts, together with any other property held by the depositary with respect to such depositary receipt.

Charges of Depositary

We will pay all transfer and other taxes and the government charges that relate solely to the depositary arrangements. We will also pay the charges of each depositary, including charges in connection with the initial

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deposit of the related series of preferred stock, the initial issuance of the depositary shares, and all withdrawals of shares of the related series of preferred stock. However, holders of depositary receipts will pay the fees and expenses of the depositary for any duties requested by such holders to be performed which are outside of those expressly provided for in the deposit agreement.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering written notice of its decision to us. We may remove the depositary at any time. Any resignation or removal will take effect when we appoint a successor depositary. We must appoint the successor depositary within a specified time after delivery of the notice of resignation or removal. The successor depositary shall be a bank or trust company that has its principal office in the United States and has a combined capital and surplus of at least $50,000,000.

Miscellaneous

We will be required to furnish certain information to the holders of the preferred stock underlying any depositary shares. The depositary, as the holder of the underlying preferred stock, will forward any report or information it receives from us to the holders of depositary shares.

Neither we nor the depositary will be liable if its ability to perform its obligations under the deposit agreement is prevented or delayed by law or any circumstance beyond its control. Both we and the depositary will be obligated to use our best judgment and to act in good faith in performing our respective duties under the deposit agreement. We and the depositary will be liable only for gross negligence and willful misconduct in performing our respective duties under the deposit agreement. Neither we nor the depositary will be obligated to appear in, prosecute or defend any legal proceeding with respect to any depositary receipts, depositary shares or preferred stock unless we or the depositary receive what we, in our sole discretion, determine to be a satisfactory indemnity from one or more holders of the depositary shares. We and the depositary will evaluate any proposed indemnity in order to determine whether the financial protection afforded by the indemnity is sufficient to reduce each party’s risk to a satisfactory and customary level. We and the depositary may rely on the advice of legal counsel or accountants of the choice of each. We and the depositary may also rely on information provided by persons we and they believe, in good faith, to be competent, and on documents we and they believe, in good faith, to be genuine.

The applicable prospectus supplement will identify the depositary’s corporate trust office. Unless the prospectus supplement indicates otherwise, the depositary will act as transfer agent and registrar for depositary receipts, and if we redeem shares of preferred stock, the depositary will act as redemption agent for the corresponding depositary receipts.

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We, each depositary, and any agent of ours or the applicable depositary may treat the registered owner of any depositary share as the absolute owner of the depositary shares for all purposes, including making payment, regardless of whether any payment in respect of the depositary share is overdue and regardless of any notice to the contrary.

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DESCRIPTION OF WARRANTS

General

We may issue warrants to purchase our debt securities, common stock or preferred stock or units of two or more of these types of securities, which are collectively referred to in this prospectus as “underlying warrant securities.” We may issue warrants independently or together with any underlying warrant securities and such warrants may be attached to or separate from those underlying warrant securities. We will issue the warrants under warrant agreements to be entered into between us and a bank or trust company, as warrant agent, as more fully described in the applicable prospectus supplement. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

The applicable prospectus supplement will contain a description of the following terms:

Exercise of Warrants

Each warrant will entitle its holder to purchase, for cash and/or securities (as will be specified in the applicable prospectus supplement), the amount or number of debt securities, shares of preferred stock, or shares of common stock, at the exercise price, as will in each case be set forth in, or be determinable as set forth in, the applicable

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prospectus supplement. Holders may exercise warrants at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement relating to the warrants offered thereby. After the close of business on the expiration date, unexercised warrants will become void.

Holders of warrants may exercise their respective warrants in the manner set forth in the applicable prospectus supplement relating to such warrants. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the underlying warrant securities purchasable upon exercise of the warrants. If a holder exercises less than all of the warrants represented by the warrant certificate, the warrant agent will issue a new warrant certificate for the remaining warrants.

Prior to the exercise of any warrants to purchase debt securities or other securities, including shares of preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the debt securities or other securities, including shares of preferred stock or common stock purchasable upon exercise, including:

The descriptions of the warrant agreements in this prospectus and in any prospectus supplement are summaries of certain material provisions of the applicable warrant agreements. These descriptions do not restate those agreements in their entirety and do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of the applicable warrant agreement and warrant certificate relating to the warrants because they, and not the summaries, define your rights as holders of the warrants or any warrant units. For more information, please review the forms of these documents, which will be filed with the SEC and will be available as described under the heading “Where You Can Find More Information” above.

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DESCRIPTION OF PURCHASE CONTRACTS

As may be specified in a prospectus supplement, we may issue purchase contracts obligating holders to purchase from us, and obligating us to sell to the holders, a number of debt securities, shares of our common stock, preferred stock or depositary shares or warrants, at a future date or dates. The price per purchase contract security may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula set forth in the purchase contracts. Under the purchase contracts, we may be required to make periodic payments to the holders of the units or vice versa. These payments may be unsecured or prefunded on some basis to be specified in the applicable prospectus supplement.

The purchase contracts may require holders to secure their obligations under the contracts in a specified manner and, in specified circumstances, we may deliver newly issued prepaid purchase contracts, or prepaid securities, when we transfer to a holder any collateral securing the holder’s obligations under the original purchase contract.

The purchase contracts may be issued separately or as part of units consisting of a purchase contract and one or more other securities, which may include our debt securities, depositary shares, preferred securities, common stock, warrants or debt obligations or government securities, and which may secure the holder’s obligations to purchase the purchase contract security under the purchase contract.

The applicable prospectus supplement relating to any purchase contracts we are offering will specify the material terms of the purchase contracts, whether they will be issued separately or as part of units, and any applicable pledge or depository arrangements.

The descriptions of the purchase contracts and any applicable underlying security or pledge or depository arrangements in this prospectus and in any prospectus supplement are summaries of certain material provisions of the applicable agreements. These descriptions do not restate those agreements in their entirety and do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of the applicable agreements because they, and not the summaries, define your rights as holders of the purchase contracts. We will make copies of the relevant agreements available as described under the heading “Where You Can Find More Information” above.

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DESCRIPTION OF UNITS

As specified in the applicable prospectus supplement, we may issue units comprised of one or more of the other securities described in this prospectus in any combination. Each unit may also include debt obligations of third parties, such as U.S. Treasury securities. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The prospectus supplement will describe:

The descriptions of the units and any applicable underlying security or pledge or depository arrangements in this prospectus and in any prospectus supplement are summaries of the material provisions of the applicable agreements. These descriptions do not restate those agreements in their entirety and do not contain all of the information that you may find useful or that may be important to you. You should refer to the provisions of the applicable agreements because they, and not the summaries, define your rights as holders of the units. We will make copies of the relevant agreements available as described under the heading “Where You Can Find More Information” above.

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PLAN OF DISTRIBUTION

We or the selling securityholders may sell the offered securities:

The prospectus supplement relating to a series of the offered securities will set forth its offering terms, including the name or names of any underwriters, dealers or agents, the purchase price of the offered securities and the proceeds to us and/or selling securityholders from the sale, any underwriting discounts, commissions and other items constituting underwriters’ compensation, any initial public offering price and any underwriting discounts, commissions and other items allowed or reallowed or paid to dealers or agents and any securities exchanges on which the offered securities may be listed.

We or a selling securityholder may use one or more underwriters in the sale of the offered securities, in which case the offered securities will be acquired by the underwriter or underwriters for their own account and may be resold from time to time in one or more transactions either:

We or a selling securityholder may directly solicit offers to purchase offered securities. Agents designated by us or a selling securityholder from time to time may also solicit offers to purchase offered securities. Any agent designated by us or a selling securityholder, who may be deemed to be an “underwriter” as that term is defined in the Securities Act, involved in the offer or sale of the offered securities in respect of which this prospectus is delivered will be named, and any commissions payable by us or a selling securityholder to such agent will be set forth in the prospectus supplement.

If a dealer is utilized in the sale of the offered securities in respect of which this prospectus is delivered, we or the selling securityholder will sell the offered securities to the dealer, as principal. The dealer, who may be deemed to be an “underwriter” as that term is defined in the Securities Act, may then resell the offered securities to the public at varying prices to be determined by the dealer at the time of resale.

If an underwriter is, or underwriters are, used in the sale, we or a selling securityholder will execute an underwriting agreement with the underwriters at the time of sale to the underwriters. The names of the underwriters will be set forth in the applicable prospectus supplement, which will be used by the underwriter to make resales of the offered securities in respect of which this prospectus is delivered to the public. In connection with the sale of offered securities, the underwriter may be deemed to have received compensation from us or the selling securityholder in the form of underwriting discounts or commissions and may also receive commissions from purchasers of offered securities for whom they may act as agents. Underwriters may also sell offered securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents.

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If so indicated in the applicable prospectus supplement, we or a selling securityholder will authorize underwriters, dealers or other persons to solicit offers by certain institutions to purchase offered securities from us or a selling securityholder at the public offering price set forth in the applicable prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a future date or dates. Institutions with which these contracts may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and others. The obligations of any purchasers under any delayed delivery contract will not be subject to any conditions except that:

The underwriters, dealers and other persons will not have any responsibility in respect of the validity or performance of such purchase contracts. The prospectus supplement relating to the purchase contracts will set forth the price to be paid for offered securities pursuant to the purchase contracts, the commission payable for solicitation of the contracts and the date or dates in the future for delivery of offered securities pursuant to the purchase contracts.

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us or a selling securityholder. Any remarketing firm will be identified and the terms of its agreement, if any, with us or a selling securityholder and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters in connection with their remarketing of offered securities.

Unless otherwise set forth in the applicable prospectus supplement, the obligations of underwriters to purchase the offered securities will be subject to certain conditions precedent, and such underwriters will be obligated to purchase all such securities, if any are purchased. In connection with the offering of securities, we may grant to the underwriters an option to purchase additional securities to cover over-allotments at the initial public offering price, with an additional underwriting commission, as may be set forth in the accompanying prospectus supplement. If we grant any over-allotment option, the terms of such over-allotment option will be set forth in the prospectus supplement for such securities.

Underwriters, dealers, remarketing firms and agents may be entitled, under agreements that may be entered into with us or a selling securityholder, to indemnification by us or a selling securityholder against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which they may be required to make in respect thereof and may engage in transactions with, or perform services for, us or the selling securityholder in the ordinary course of business.

Any underwriter may engage in over-allotment, stabilizing transactions, short-covering transactions and penalty bids in accordance with Regulation M under the Securities Exchange Act. Over-allotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short-covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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Sales by Selling Securityholders

Selling securityholders may use this prospectus in connection with the resale of securities. The applicable prospectus supplement will identify the selling securityholders and the terms of the securities. Selling securityholders may be deemed to be underwriters in connection with the securities they resell and any profits on the sales may be deemed to be underwriting discounts and commissions under the Securities Act. The selling securityholders will receive all the proceeds from the sale of securities. We will not receive any proceeds from sales by selling securityholders.

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LEGAL MATTERS

In connection with particular offerings of the securities in the future, and if stated in the applicable prospectus supplement, the validity of those securities and certain U.S. federal income tax matters may be passed upon for us by Troutman Pepper Hamilton Sanders LLP (Washington, DC), and for the underwriters or agents by counsel named in the applicable prospectus supplement.

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EXPERTS

Our consolidated financial statements appearing in our Annual Report on Form 10-K for the year ended December 31, 2023, have been audited by RSM US LLP, an independent registered public accounting firm, as set forth in their report included therein and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

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Western Alliance Bancorporation

Debt Securities

Common Stock

Preferred Stock

Depositary Shares

Purchase Contracts

Units

Warrants

Prospectus

May 8, 2024

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Estimated fees and expenses, other than underwriting discounts and commissions, payable by Western Alliance in connection with the issuance and distribution of the offered securities as follows:

Western Alliance is a Delaware corporation subject to the applicable indemnification provisions of the General Corporation Law of the State of Delaware, which is referred to herein as the Delaware Corporation Law. Section 145 of the Delaware Corporation Law provides for the indemnification, under certain circumstances, of persons who are or were directors, officers, employees or agents of Western Alliance, or are or were serving at the request of Western Alliance in such a capacity with another business organization or entity, against expenses, judgments, fines and amounts paid in settlement in actions, suits or proceedings, whether civil, criminal, administrative, or investigative, brought or threatened against or involving such persons because of such person’s service in any such capacity if the indemnitee acted in good faith and in a manner they reasonably believed to be in or not opposed to Western Alliance’s best interests, and, with respect to any criminal action, had no reasonable cause to believe their conduct was unlawful. In the case of actions brought by or in the right of Western Alliance, Section 145 provides for indemnification only of expenses if the indemnitee acted in good faith and in a manner they reasonably believed to be in or nor opposed to Western Alliance’s best interest and no indemnification may be paid if the indemnitee is judged liable unless, and only upon a determination by the Court of Chancery or the court in which such action or suit was brought that, in view of all the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses.

Article Eighth of Western Alliance’s certificate of incorporation provides that, to the fullest extent permitted by applicable law as then in effect, no director or officer shall be personally liable to us or any stockholder for monetary damages for breach of fiduciary duty as a director or officer, except for liability (i) for any breach director’s duty of loyalty to us or our stockholders, (ii) for acts or omissions not in good faith or which involved intentional misconduct or a knowing violation of law, (iii) under Section 174 of the Delaware Corporation Law, or (iv) for any transaction from which the director derived an improper personal benefit.

Article VII of Western Alliance’s bylaws provides for indemnification of its directors, officers, employees and agents, and for those serving in such roles with other business organizations or entities, in the event that such person was or is made a party to (or is threatened to be made a party to) any civil, criminal, administrative or investigative action, suit or proceeding (other than an action by or in the right of Western Alliance) by reason of the fact that such person is or was serving in such a capacity for or on behalf of Western Alliance. Western Alliance will indemnify any such person against all expenses, liability and loss reasonably incurred or suffered

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by such person in connection therewith; provided, however, that it shall indemnify any such person seeking indemnity in connection with a proceeding (or part thereof) initiated by such person only if (a) such indemnification is expressly required to be made by law, (b) the proceeding (or part thereof) was authorized by the board of directors, (c) such indemnification is provided by Western Alliance, in its sole discretion, pursuant to the powers vested in the corporation under the Delaware Corporation Law, or (d) the proceeding (or part thereof) is brought to establish or enforce a right to indemnification or advancement under an indemnity agreement or any other statute or law or otherwise as required under Section 145 of the Delaware Corporation Law.

Western Alliance has entered into indemnification agreements with certain of its directors and executive officers in addition to indemnification provided for in its bylaws. Western Alliance maintains, on behalf of its directors and officers, insurance protection against certain liabilities arising out of the discharge of their duties, as well as insurance covering it for indemnification payments made to its directors and officers for certain liabilities. The premiums for such insurance are paid by Western Alliance.

The Exhibit Index included herewith is incorporated herein by reference.

Item 17. Undertakings.

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Filing Fee Tables” or “Calculation of Registration Fee” table, as applicable, in the effective registration statement.;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (i), (ii) and (iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

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(4) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which the prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6) That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the

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securities being registered, the registrant will, unless in the opinion of its counsel the has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

(8) To file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act.

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INDEX TO EXHIBITS

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Phoenix, State of Arizona, on May 8, 2024.

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Kenneth Vecchione and Dale M. Gibbons, and each and any of them, his or her true and lawful attorney-in-fact and agent, each acting alone, with full and several power of substitution, for him or her and his or her name, place and stead, in any and all capacities, to sign any and all amendments to this registration statement, and to file the same, with all exhibits thereto, and all documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agents or any of them, or their substitutes, may lawfully do or cause to be done.

Pursuant to the requirement of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities indicated as of May 8, 2024:

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Exhibit 5.1

Troutman Pepper Hamilton Sanders LLP 401 9th Street, NW Suite 1000 Washington, DC 20004   troutman.com

May 8, 2024

Board of Directors

Western Alliance Bancorporation

One E. Washington Street, Suite 1400

Phoenix, Arizona 85004

Ladies and Gentlemen:

We are acting as counsel to Western Alliance Bancorporation, a Delaware corporation (the “Company”), in connection with the preparation of the Company’s registration statement on Form S-3ASR (the “Registration Statement”), filed on the date hereof with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”). The Registration Statement relates to the issuance and sale from time to time by the Company, pursuant to Rule 415 of the General Rules and Regulations promulgated under the Act, of the following securities of the Company:

(i) shares of common stock, $0.0001 par value per share (the “Common Stock”);

(ii) shares of preferred stock, $0.0001 par value per share, in one or more series (the “Preferred Stock”);

(iii) Preferred Stock represented by depositary receipts (the “Depositary Shares”) issued pursuant to one or more deposit agreements between the Company and a bank or trust company, as depositary (each, a “Depositary Agreement”);

(iv) unsecured debt securities (the “Debt Securities”), which may be either senior debt securities or subordinated debt securities and which may be issued in one or more series under one or more indentures (each, an “Indenture” and, collectively, “Indentures”), entered into or proposed to be entered into between the Company and a trustee to be identified in the Indenture as trustee (the “Trustee”);

(v) warrants to purchase (a) Debt Securities (the “Debt Warrants”), (b) Preferred Stock (the “Preferred Stock Warrants”), or (c) Common Stock (the “Common Stock Warrants” and, collectively with the Debt Warrants and the Preferred Stock Warrants, the “Warrants”), which may be issued pursuant to one or more warrant agreements (each, a “Warrant Agreement”) proposed to be entered into between the Company and warrant agents to be named therein (each, a “Warrant Agent” and, collectively, “Warrant Agents”);

(vi) purchase contracts representing an obligation to purchase Debt Securities, Preferred Stock, Common Stock, Warrants or Depositary Shares (the “Purchase Contracts”), which may be issued under one or more purchase contract agreements proposed to be entered into by the Company (the “Purchase Contract Agreements”);

Western Alliance Bancorporation May 8, 2024 Page 2

(vii) units consisting of any combination of two or more Offered Securities (as defined herein) (the “Units”), which may be issued under one or more unit agreements proposed to be entered into by the Company (the “Unit Agreements”); and

(viii) such indeterminate number of shares of Common Stock, Preferred Stock or Depositary Shares and amount of Debt Securities, Warrants, Purchase Contracts and Units, as may be issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Depositary Shares, Debt Securities, Warrants, Purchase Contracts or Units, including such shares of Common Stock, Preferred Stock or Depositary Shares as may be issued pursuant to anti-dilution adjustments, in amounts, at prices and on terms to be determined at the time of offering (collectively, “Indeterminate Securities”).

Together, the Common Stock, Preferred Stock, Depositary Shares, Debt Securities, Warrants, Purchase Contracts, Units, and Indeterminate Securities are the “Offered Securities,” all of which may be sold from time to time and on a delayed or continuous basis, as set forth in the prospectus which forms a part of the Registration Statement (the “Prospectus”), and as to be set forth in one or more supplements to the Prospectus.

This opinion letter is being furnished in accordance with the requirements of Item 601(b)(5)(i) of Regulation S-K.

For purposes of this opinion letter, we have examined originals or copies, certified or otherwise identified to our satisfaction, of such corporate records, agreements, and other instruments, certificates, orders, opinions, correspondence with public officials, certificates provided by the Company’s officers and representatives, and other documents as we have deemed necessary or advisable for the purposes of rendering the opinion set forth herein, including (i) the corporate and organizational documents of the Company, including the Amended and Restated Certificate of Incorporation, as amended to date (the “Articles”), and the Bylaws of the Company, as amended to date (the “Bylaws”), (ii) the resolutions of the Board of Directors of the Company with respect to the Registration Statement and the registration of the Offered Securities, (iii) a specimen certificate representing the Company’s common stock and (iv) the Registration Statement and exhibits thereto, including the Prospectus.

For purposes of the opinions expressed below, we have assumed (i) the authenticity of all documents submitted to us as originals, (ii) the conformity to the originals of all documents submitted as certified, photostatic or electronic copies and the authenticity of the originals thereof, (iii) the legal capacity of natural persons, (iv) the genuineness of signatures not witnessed by us, (v) the due authorization, execution and delivery of all documents by all parties, other than the Company, and the validity, binding effect and enforceability thereof and (vi) the truth, accuracy and completeness of the information, representations and warranties contained in the records, documents, instruments and certificates we have reviewed.

As to any facts material to the opinions expressed herein which were not independently established or verified, we have relied upon oral or written statements and representations of officers and other representatives of the Company and others and of public officials. In making our examination of documents executed or to be executed, we have assumed that the parties thereto, other than the Company, had or will have the power, corporate or other, to enter into and perform all obligations thereunder and have also assumed the due authorization by all requisite action, corporate or other, and the execution and delivery by such parties of such documents, and the validity and binding effect thereof on such parties.

Western Alliance Bancorporation May 8, 2024 Page 3

We have further assumed that (i) the Registration Statement and any amendment thereto will have become effective under the Act (and will remain effective under the Act at the time of issuance of the Offered Securities thereunder), (ii) any prospectus supplement or term sheet describing the Offered Securities will be filed with the Commission to the extent required by applicable law and relevant rules and regulations of the Commission, (iii) the Depositary Agreements, Indentures, Purchase Contracts, the Purchase Contract Agreements, the Warrants, the Warrant Agreements, the Units and the Unit Agreements have been or will be duly authorized, executed and delivered by the parties thereto, and, in the case of the Indentures, in substantially the form reviewed by us, and that any Debt Securities, Purchase Contracts, Warrants or Units, as the case may be, that may be issued will be manually authenticated, signed or countersigned, as the case may be, by duly authorized officers of the parties thereto and that each will be governed by the laws of the State of New York, (iv) that a definitive purchase, underwriting or similar agreement with respect to any Offered Securities offered thereby will have been duly authorized and validly executed and delivered by the Company and the other parties thereto and (v) the Board of Directors of the Company, an authorized committee thereof or appropriate officers of the Company will have taken all necessary corporate action with respect to the issuance of the Offered Securities, the instruments pursuant to which they are duly authorized and established and related matters.

In addition, we have assumed that the terms of the Offered Securities will have been established so as not to, and that the execution and delivery by the Company of, and the performance of its obligations under, the Depositary Agreements, the Indentures, the Offered Securities of the Company, the Purchase Contracts, the Purchase Contract Agreements, the Warrants, the Warrant Agreements, the Units and the Unit Agreements, will not violate, conflict with or constitute a default under (i) any agreement or instrument to which the Company or its properties are subject, (ii) any law, rule or regulation to which the Company or its properties is subject, (iii) any judicial or regulatory order or decree of any governmental authority or (iv) any consent, approval, license, authorization or validation of, or filing, recording or registration with, any governmental authority.

This opinion letter is based as to matters of law solely on the federal laws of the United States of America, the Delaware General Corporation Law, as amended, and the laws of the State of New York and we express no opinion as to the effect of the laws of any other jurisdiction or as to the securities or blue sky laws of any state (including, without limitation, Delaware and New York), municipal law or the laws of any local agencies within any state (including, without limitation, Delaware and New York). This opinion is limited to the matters stated herein, and no opinion is implied or may be inferred beyond the matters expressly stated herein. As used herein, the term “Delaware General Corporation Law, as amended” includes the statutory provisions contained therein, all applicable provisions of the Delaware Constitution and reported judicial decisions interpreting these laws.

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Based on the foregoing and in reliance thereon, and subject to the limitations, qualifications, assumptions, exceptions, and other matters set forth herein, we are of the opinion that:

1. With respect to the shares of any Common Stock offered by the Company, including any Indeterminate Securities (the “Offered Common Stock”), when (a) if certificated, certificates in the form required under the Delaware General Corporation Law, as amended, representing the shares of Offered Common Stock are duly executed and countersigned; and (b) the shares of Offered Common Stock are registered in the Company’s share registry and delivered upon payment of the agreed-upon consideration therefore, the shares of Offered Common Stock (including any Common Stock duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable underwriting agreement, if any, or any other duly authorized, executed and delivered valid and binding agreement, will be duly authorized, validly issued, fully paid and nonassessable.

2. With respect to the shares of any series of Preferred Stock offered by the Company, including any Indeterminate Securities (the “Offered Preferred Stock”), when (a) if certificated, certificates in the form required under the Delaware General Corporation Law, as amended, representing the shares of Offered Preferred Stock are duly executed and countersigned; (b) articles of amendment for the particular series of Offered Preferred Stock have been filed with the Secretary of State of the State of Delaware (the “SOS”) and the SOS has issued a certificate of amendment with respect thereto; and (c) the shares of Offered Preferred Stock are registered in the Company’s share registry and delivered upon payment of the agreed-upon consideration therefore, the shares of the Offered Preferred Stock (including any Preferred Stock duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable underwriting agreement, if any, or any other duly authorized, executed and delivered valid and binding agreement, will be duly authorized, validly issued, fully paid and nonassessable.

3. With respect to any Depositary Shares offered by the Company, including any Indeterminate Securities (the “Offered Depositary Shares”), when (a) if certificated, certificates in the form required under the Delaware General Corporation Law, as amended, representing the shares of Preferred Stock underlying the Offered Depositary Shares (the “Underlying Preferred Stock”) are duly executed and countersigned; (b) articles of amendment for the particular series of Underlying Preferred Stock have been filed with the SOS and the SOS has issued a certificate of amendment with respect thereto; (c) the Offered Depositary Shares are registered in the Company’s share registry and delivered upon payment of the agreed-upon consideration therefore; (d) the applicable Depositary Agreement has been duly authorized, executed and delivered by each of the Company and the depositary; (e) the shares of the Underlying Preferred Stock have been deposited with the depositary under the Depositary Agreement; and (f) the depositary receipts representing the Offered Depositary Shares have been duly executed, countersigned, registered and delivered to the purchasers thereof upon payment of the agreed-upon consideration therefor: (1) the Offered Depositary Shares, when issued and sold in accordance with the applicable underwriting agreement, if any, or any other duly authorized, executed and delivered valid and binding agreement, will be duly authorized, validly issued, fully paid and nonassessable, and the depositary receipts representing the Offered Depositary Shares will entitle the holders thereof to the rights specified therein and in the Depositary Agreement; and (2) the Underlying Preferred Stock will be duly authorized, validly issued, fully paid and nonassessable.

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4. With respect to any series of Debt Securities offered by the Company, including any Indeterminate Securities (the “Offered Debt Securities”), when the Offered Debt Securities have been duly executed and authenticated in accordance with the provisions of the applicable Indenture and duly delivered to the purchasers thereof upon payment of the agreed-upon consideration therefor, the Offered Debt Securities (including any Debt Securities duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable Indenture and the applicable underwriting agreement, if any, or any other duly authorized, executed and delivered valid and binding agreement, will be valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms, except to the extent that enforcement thereof may be limited by: (a) bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws now or hereafter in effect relating to creditors’ rights generally; (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity); (c) public policy considerations which may limit the rights of parties to obtain remedies; (d) the waivers of any usury defense contained in the Indenture or Offered Debt Securities which may be unenforceable; (e) requirements that a claim with respect to any Offered Debt Securities denominated in a currency, currency unit or composite currency other than United States dollars (or a judgment denominated other than in United States dollars in respect of such claim) be converted into United States dollars at a rate of exchange prevailing on a date determined pursuant to applicable law; and (f) governmental authority to limit, delay or prohibit the making of payments outside the United States or in foreign currencies, currency units or composite currencies.

5. With respect to any Warrants offered by the Company, including any Indeterminate Securities (the “Offered Warrants”), when the Offered Warrants have been duly executed, delivered and countersigned in accordance with the provisions of the applicable Warrant Agreement and duly issued and sold in the applicable form to be filed as an exhibit to the Registration Statement or any amendment thereto and in the manner contemplated in the Registration Statement or any prospectus supplement or term sheet relating thereto, the Offered Warrants (including any Warrants duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable Warrant Agreement and the applicable underwriting agreement or any other duly authorized, executed and delivered valid and binding agreement, will be duly authorized and validly issued and will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms, except to the extent that enforcement thereof may be limited by: (a) bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws now or hereafter in effect relating to creditors’ rights generally; (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity); and (c) public policy considerations which may limit the rights of parties to obtain remedies.

6. With respect to any Purchase Contracts offered by the Company, including any Indeterminate Securities (the “Offered Purchase Contracts”), when the applicable Offered Purchase Contracts have been duly executed and delivered and duly issued and sold in the applicable form to be filed as an exhibit to the Registration Statement or any amendment thereto and in the manner contemplated in the Registration Statement or any prospectus supplement or term sheet relating thereto, the Offered Purchase Contracts (including any

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Purchase Contracts duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable Purchase Contract Agreement and the applicable underwriting agreement or any other duly authorized, executed and delivered valid and binding agreement, will be duly authorized and validly issued and will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms, except to the extent that enforcement thereof may be limited by: (a) bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws now or hereafter in effect relating to creditors’ rights generally; (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and (c) public policy considerations which may limit the rights of parties to obtain remedies.

7. With respect to any Units, including any Indeterminate Securities (the “Offered Units”), when (a) any Debt Securities of the Company included in such Offered Units have been duly issued and paid for in the manner contemplated in the Registration Statement and any prospectus supplement relating thereto; and (b) the Offered Units have been duly executed, delivered, countersigned, issued and sold in accordance with the provisions of the applicable Unit Agreement in the applicable form to be filed as an exhibit to the Registration Statement or any amendment thereto and in the manner contemplated in the Registration Statement or any prospectus supplement or term sheet relating thereto, the Offered Units (including any Units duly issued upon exercise, settlement, exchange or conversion of any Preferred Stock, Debt Securities, Warrants, Purchase Contracts or Units), when issued and sold in accordance with the applicable Unit Agreement and the applicable purchase agreement or any other duly authorized, executed and delivered valid and binding agreement, or upon due conversion, exercise or exchange of any Debt Securities, will be valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms, except to the extent that enforcement thereof may be limited by: (y) bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws now or hereafter in effect relating to creditors’ rights generally and (z) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity).

Our opinion is as of the date hereof and we have no responsibility to update this opinion for events and circumstances occurring after the date hereof or as to facts relating to prior events that are subsequently brought to our attention and we disavow any undertaking to advise you of any changes in law.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the Registration Statement and to the use of our name under the caption “Legal Matters” in the Prospectus and Registration Statement. In giving this consent, we do not hereby admit that we come within the category of persons whose consent is required under Section 7 of the Act or the rules or regulations of the Commission promulgated thereunder.

Exhibit 23.2

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in this Registration Statement on Form S-3 and related Prospectus, as filed on May 8, 2024, of Western Alliance Bancorporation of our reports dated February 27, 2024, relating to the consolidated financial statements and the effectiveness of internal control over financial reporting of Western Alliance Bancorporation, appearing in the Annual Report on Form 10-K of Western Alliance Bancorporation for the year ended December 31, 2023. We also consent to the reference to our firm under the heading “Experts” in such Prospectus.

/s/ RSM US LLP

Austin, Texas

May 8, 2024

1

Exhibit 107

Calculation of Filing Fee Tables

Form S-3

(Form Type)

Western Alliance Bancorporation

(Exact Name of Registrant as Specified in its Charter)

Table 1-Newly Registered Securities