SCHEDULE 13D/A 0000902664-26-000513 0002040262 XXXXXXXX LIVE 1 Class A Common Stock, $0.0001 par value per share 02/03/2026 false 0001441683 03782L101 APPIAN CORP

7950 JONES BRANCH DRIVE MCLEAN VA 22102

Carly Pollock (415) 318-7900 Fivespan Partners, LP 1170 Gorgas Avenue San Francisco CA 94129 0002040262 N Fivespan Partners, LP AF N DE 0.00 3380907.00 0.00 3380907.00 3380907.00 N 7.9 IA PN Y Dylan Haggart AF N Z4 0.00 3380907.00 0.00 3380907.00 3380907.00 N 7.9 IN HC Class A Common Stock, $0.0001 par value per share APPIAN CORP 7950 JONES BRANCH DRIVE MCLEAN VA 22102 This Amendment No. 1 ("Amendment No. 1") amends and supplements the statement on Schedule 13D (the "Schedule 13D") relating to the shares of Class A Common Stock, par value $0.0001 per share (the "Common Stock"), of Appian Corporation, a Delaware corporation (the "Issuer"). This Amendment No. 1 amends and restates the first sentence of Item 3 and Item 5 as set forth below. Capitalized terms used herein and not otherwise defined in this Amendment No. 1 have the meanings set forth in the Schedule 13D. The Reporting Persons used a total of approximately $100.5 million (excluding brokerage commissions) to acquire the shares of Common Stock reported herein. The source of the funds used to acquire the shares of Common Stock reported herein was the working capital of the Fivespan Fund. See rows (11) and (13) of the cover pages to this Schedule 13D for the aggregate number of shares of Common Stock and percentages of the shares of Common Stock beneficially owned by each of the Reporting Persons. All percentages set forth herein are based upon a total of 42,735,083 shares of Common Stock outstanding as of November 3, 2025, as reported in the Issuer's quarterly report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the SEC on November 6, 2025. See rows (7) through (10) of the cover pages to this Schedule 13D for the number of shares of Common Stock as to which each Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition. Information concerning transactions in the Common Stock of the Issuer since the filing of the Schedule 13D is set forth in Schedule A attached hereto and is incorporated herein by reference. No person other than the Reporting Persons and the Fivespan Fund is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the shares of Common Stock reported herein. Not applicable. Fivespan Partners, LP /s/ Carly Pollock 02/05/2026 Dylan Haggart /s/ Dylan Haggart 02/05/2026