UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 2131, 2025

WESTERN ALLIANCE BANCORPORATION

(Exact name of registrant as specified in its charter)

Delaware

001-32550

88-0365922

(State or other jurisdiction
of incorporation)

(Commission
File Number)

(IRS Employer
Identification No.)

One E. Washington Street, Phoenix, Arizona 85004

(Address of principal executive offices) (Zip Code)

(602) 389-3500

(Registrant's telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.0001 Par Value

WAL

New York Stock Exchange

Depositary Shares, Each Representing a 1/400th Interest in a Share of

4.250% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series A

WAL PrA

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

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 13(a) of the Exchange Act. ¨

ITEM 28.0201. ~~RESULTS~~OTHER ~~OF OPERATIONS AND FINANCIAL CONDITION~~EVENTS.

OnQuarterly ~~October 21,~~Common ~~2025, Western Alliance Bancorporation (the “Company”) issued a press release reporting results for the fiscal quarter ended September 30, 2025~~ and ~~posted~~Preferred onStock ~~its website its third quarter 2025 Earnings Conference Call Presentation, which contains certain additional historical and forward-looking information relating to the Company~~Dividend. ~~Copies of the press release and presentation slides are attached hereto as Exhibits 99.1 and 99.2, respectively.~~

~~The~~Pursuant ~~information~~to ina ~~this~~unanimous ~~report~~written ~~(including~~consent, ~~Exhibits~~dated ~~99.1~~October ~~and~~31, ~~99.2~~2025, ~~hereto) is being “furnished” and shall not be deemed “filed” for~~ the ~~purposes~~Board of ~~Section~~Directors ~~18 of~~ (the ~~Securities~~"Board") ~~Exchange Act~~ of ~~1934,~~Western asAlliance ~~amended,~~Bancorporation isdeclared ~~not~~a ~~subject~~quarterly tocash ~~the~~dividend ~~liabilities~~ of ~~that~~$0.42 ~~section~~per ~~and~~share isof ~~not~~common ~~deemed~~stock ~~incorporated~~(the by"Common ~~reference~~Stock inDividend"). ~~any~~The ~~filing~~Common ~~under~~Stock ~~the~~Dividend ~~Securities~~will ~~Act~~be ofpayable ~~1933,~~November ~~as amended~~28, or2025 ~~the~~to ~~Securities~~shareholders ~~Exchange Act~~ of ~~1934,~~record as ~~amended,~~of ~~except~~November as13, ~~shall be expressly set forth by specific reference in such filing~~2025.

The Board also declared a quarterly cash dividend of $106.25 per share (equivalent to $0.265625 per depositary share) on its 4.250% Fixed Rate Reset Non-Cumulative Perpetual Preferred Stock, Series A (the "Preferred Stock Dividend"). The Preferred Stock Dividend will be payable December 30, 2025 to shareholders of record as of December 15, 2025.

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.

(d) Exhibits.

99.1						Press Release dated October 21, 2025
99.2						Third Quarter 2025 Earnings Conference Call dated October 22, 2025
104						Cover Page Interactive Data File (embedded within the Inline XBRL document)


104						Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			WESTERN ALLIANCE BANCORPORATION
			(Registrant)
			/s/ Dale Gibbons
			Dale Gibbons
			Vice Chairman and
			Chief Financial Officer
Date:			October 2131, 2025

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