X0202 SCHEDULE 13G/A 0001104659-26-016343 0001674546 XXXXXXXX LIVE 1 Common Stock 06/30/2026 0001798749 Jade Biosciences, Inc. 008064206 221 CRESCENT ST. BUILDING 23, SUITE 105 WALTHAM MA 02453 Rule 13d-1(b) Bellevue Group AG a V8 0.00 3057996.00 0.00 3057996.00 3057996.00 N 5.0 HC CO The percentages of beneficial ownership contained herein are based on 60,845,967 shares of Common Stock outstanding as of June 5, 2026 (after giving effect to the closing of an equity offering by the Issuer on such date), as reported by the Issuer in its Prospectus Supplement filed with the SEC on June 4, 2026 and its Press Release issued on June 5, 2026. Bellevue Asset Management AG a V8 0.00 3057996.00 0.00 3057996.00 3057996.00 N 5.0 CO The percentages of beneficial ownership contained herein are based on 60,845,967 shares of Common Stock outstanding as of June 5, 2026 (after giving effect to the closing of an equity offering by the Issuer on such date), as reported by the Issuer in its Prospectus Supplement filed with the SEC on June 4, 2026 and its Press Release issued on June 5, 2026. Jade Biosciences, Inc. 221 CRESCENT ST. BUILDING 23, SUITE 105 WALTHAM, MA, 02453 Bellevue Group AG ("Bellevue") on behalf of its wholly-owned subsidiary, Bellevue Asset Management AG ("BAM AG") Bellevue: Theaterstrasse 12, Zurich, Switzerland, CH-8001 BAM AG: Theaterstrasse 12, Zurich, Switzerland, CH-8001 Bellevue: Switzerland BAM AG: Switzerland N FI Swiss Financial Market Supervisory Authority (FINMA) 3,057,996 5.0% 0 3,057,996 0 3,057,996 Y Y N This statement is filed jointly by Bellevue and BAM AG. BAM AG is a wholly-owned subsidiary of Bellevue. Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and 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. Bellevue Group AG /s/ Stefano Montalbano 08/13/2026 /s/ Christoph Eisenring 08/13/2026 Bellevue Asset Management AG /s/ Christoph Eisenring 08/13/2026 /s/ Ivo Betschart 08/13/2026