COF: Other company developments

Item 8.01 Other Events. On August 20, 2026, Capital One Financial Corporation (the “Company”) issued a press release announcing that it will redeem all outstanding shares of its Fixed Rate Reset Non-Cumulative Perpetual Preferred Stock, Series M, $0.01 par value per share (“Series M Preferred Stock”). The Series M Preferred Stock (CUSIP: 14040HCF0) will be redeemed on September 1, 2026 (the “Series M Redemption Date”) at a redemption price of $1,000 per share of Series M Preferred Stock. All 1,000,000 outstanding shares of the Series M Preferred Stock will be redeemed on the Series M Redemption Date. Regular dividends on the outstanding shares of the Series M Preferred Stock will be paid separately on the Series M Redemption Date to holders of record as of the close of business on August 17, 2026, in the customary manner. On and after the Series M Redemption Date, all dividends on the shares of Series M Preferred Stock will cease to accrue. A copy of the press release is attached as Exhibit 99.1 hereto and incorporated by reference into this Item 8.01. Item 9.01 Financial Statements and Exhibits. (d) Exhibits Exhibit No. Description 99.1 Press Release, dated August 20, 2026 104 The cover page from this Current Report on Form 8-K, formatted in Inline XBRL 1 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the Company has duly caused this Current Report on Form 8-K to be signed on its behalf by the undersigned hereunto duly authorized. CAPITAL ONE FINANCIAL CORPORATION Date: August 20, 2026 By: /s/ Matthew W. Cooper Matthew W. Cooper General Counsel and Corporate Secretary 2