SCHEDULE 13G 0001831942 XXXXXXXX LIVE Common Stock, $0.0001 par value per share 09/26/2025 0001833214 SAB BIOTHERAPEUTICS, INC. 78397T202 777 W 41st St Suite 401 Miami Beach FL 33140 Rule 13d-1(c) Commodore Capital LP DE 0.00 4522977.00 0.00 4522977.00 4522977.00 N 9.9 IA PN Commodore Capital Master LP E9 0.00 4522977.00 0.00 4522977.00 4522977.00 N 9.9 PN Robert Egen Atkinson X1 0.00 4522977.00 0.00 4522977.00 4522977.00 N 9.9 HC IN Michael Kramarz X1 0.00 4522977.00 0.00 4522977.00 4522977.00 N 9.9 HC IN SAB BIOTHERAPEUTICS, INC. 777 W 41st St, Suite 401, Miami Beach, Florida 33140. Commodore Capital LP Commodore Capital Master LP Robert Egen Atkinson Michael Kramarz Each a "Filer." The address for Commodore Capital LP, Robert Egen Atkinson, and Michael Kramarz is 444 Madison Avenue, Floor 35, New York, NY 10022. The address for Commodore Capital Master LP is c/o Maples Corporate Services Limited, Ugland House, South Church Street, PO Box 309, Grand Cayman KY1-1104, Cayman Islands. See Item 4 of the cover page for each Filer. Y See Item 9 of the cover page for each Filer. This report on Schedule 13G is being filed by Commodore Capital LP (the "Firm"), Commodore Capital Master LP ("Commodore Master"), Michael Kramarz, and Robert Egen Atkinson. The Firm is the investment manager to Commodore Master. As of September 26, 2025, the Firm may be deemed to beneficially own an aggregate of 4,522,977 shares of Common Stock, $0.0001 par value per share (the "Common Stock"), of SAB Biotherapeutics, Inc. (the "Issuer"), consisting of (i) 4,401,500 shares of Common Stock issued to Commodore Master upon the conversion of Series B Convertible Preferred Stock, par value $0.0001 per share (the "Series B Preferred Stock"), following stock approval at a special meeting of stockholders held on September 26, 2025 and (ii) 121,477 shares of Common Stock issuable upon the conversion of Series B Preferred Stock, which is subject to a beneficial ownership limitation of 9.99% (the "Ownership Blocker"). The foregoing excludes (i) 6,897,023 shares of Common Stock issuable upon the conversion of Series B Preferred Stock, which is subject to the Ownership Blocker, (ii) 11,420,000 shares of Common Stock issuable upon the conversion of Series B Preferred Stock underlying certain enrollment warrants, which is subject to the Ownership Blocker, and (iii) 5,710,000 shares of Common Stock issuable upon the conversion of Series B Preferred Stock underlying certain release warrants, which is subject to the Ownership Blocker. The Firm, as the investment manager to Commodore Master, may be deemed to beneficially own these securities. Michael Kramarz and Robert Egen Atkinson are the managing partners of the Firm and exercise investment discretion with respect to these securities. Ownership percentages are based on 45,108,294 shares of Common Stock reported as issued and outstanding by the Issuer to the Filers. Commodore Capital LP - 9.9% Commodore Capital Master LP - 9.9% Robert Egen Atkinson - 9.9% Michael Kramarz - 9.9% Commodore Capital LP - 0 Commodore Capital Master LP - 0 Robert Egen Atkinson - 0 Michael Kramarz - 0 Commodore Capital LP - 4,522,977.00 Commodore Capital Master LP - 4,522,977.00 Robert Egen Atkinson - 4,522,977.00 Michael Kramarz - 4,522,977.00 Commodore Capital LP - 0 Commodore Capital Master LP - 0 Robert Egen Atkinson - 0 Michael Kramarz - 0 Commodore Capital LP - 4,522,977.00 Commodore Capital Master LP - 4,522,977.00 Robert Egen Atkinson - 4,522,977.00 Michael Kramarz - 4,522,977.00 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. Exhibit 1: Joint Filing Agreement Commodore Capital LP /s/ Michael Kramarz 10/03/2025 Commodore Capital Master LP /s/ Michael Kramarz 10/03/2025 Robert Egen Atkinson /s/ Robert Egen Atkinson 10/03/2025 Michael Kramarz /s/ Michael Kramarz 10/03/2025