X0202 SCHEDULE 13G/A 0001930214 XXXXXXXX LIVE 1 Common Stock, par value $0.0001 per share 06/30/2026 0001738021 Compass Therapeutics, Inc. 20454B104 80 Guest St. Suite 601 Boston MA 02135 Rule 13d-1(c) Vivo Opportunity Fund Holdings, L.P. b DE 7207573.00 0.00 7207573.00 0.00 7207573.00 N 4.0 PN The number represents shares of common stock, par value $0.0001 per share (the "Common Stock") of Compass Therapeutics, Inc. (the "Issuer") held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. The percentage of class is based on 180,087,915 shares of Common Stock outstanding, as of July 28, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission ("SEC") on August 6, 2026. Vivo Opportunity, LLC b DE 7207573.00 0.00 7207573.00 0.00 7207573.00 N 4.0 OO The number represents shares of Common Stock of the Issuer held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. The percentage of class is based on 180,087,915 shares of Common Stock outstanding, as of July 28, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 6, 2026. Vivo Opportunity Cayman Fund, L.P. b E9 549487.00 0.00 549487.00 0.00 549487.00 N 0.3 PN The number represents shares of Common Stock of the Issuer held of record by Vivo Opportunity Cayman Fund, L.P. Vivo Opportunity Cayman, LLC is the general partner of Vivo Opportunity Cayman Fund, L.P. The percentage of class is based on 180,087,915 shares of Common Stock outstanding, as of July 28, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 6, 2026. Vivo Opportunity Cayman, LLC b E9 549487.00 0.00 549487.00 0.00 549487.00 N 0.3 OO The number represents shares of Common Stock of the Issuer held of record by Vivo Opportunity Cayman Fund, L.P. Vivo Opportunity Cayman, LLC is the general partner of Vivo Opportunity Cayman Fund, L.P. The percentage of class is based on 180,087,915 shares of Common Stock outstanding, as of July 28, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 6, 2026. Compass Therapeutics, Inc. 80 Guest St., Suite 601, Boston, Massachusetts, 02135 Vivo Opportunity Fund Holdings, L.P. and its General Partner Vivo Opportunity, LLC Vivo Opportunity Cayman Fund, L.P. and its General Partner Vivo Opportunity Cayman, LLC 192 Lytton Avenue, Palo Alto, CA 94301 Vivo Opportunity Fund Holdings, L.P. is a Delaware limited partnership. Vivo Opportunity, LLC is a Delaware limited liability company. Vivo Opportunity Cayman Fund, L.P. is a Cayman Islands limited partnership. Vivo Opportunity Cayman, LLC is a Cayman Islands limited liability company. Y Vivo Opportunity, LLC beneficially owns 7,207,573 shares of Common Stock. The securities are held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity Cayman, LLC beneficially owns 549,487 shares of Common Stock. The securities are held of record by Vivo Opportunity Cayman Fund, L.P. Vivo Opportunity Cayman, LLC is the general partner of Vivo Opportunity Cayman Fund, L.P. Vivo Opportunity Fund Holdings, L.P.: 4.0% Vivo Opportunity, LLC: 4.0% Vivo Opportunity Cayman Fund, L.P.: 0.3% Vivo Opportunity Cayman, LLC.: 0.3 % Vivo Opportunity Fund Holdings, L.P.: 7,207,573 shares Vivo Opportunity, LLC: 7,207,573 shares Vivo Opportunity Cayman Fund, L.P.: 549,487 shares Vivo Opportunity Cayman, LLC: 549,487 shares 0 Vivo Opportunity Fund Holdings, L.P.: 7,207,573 shares Vivo Opportunity, LLC: 7,207,573 shares Vivo Opportunity Cayman Fund, L.P.: 549,487 shares Vivo Opportunity Cayman, LLC: 549,487 shares 0 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Vivo Opportunity Fund Holdings, L.P. /s/ Kevin Dai 08/14/2026 Vivo Opportunity, LLC /s/ Kevin Dai 08/14/2026 Vivo Opportunity Cayman Fund, L.P. /s/ Kevin Dai 08/14/2026 Vivo Opportunity Cayman, LLC /s/ Kevin Dai 08/14/2026