X0202 SCHEDULE 13G/A 0000918923 XXXXXXXX LIVE 7 Common Stock, par value $0.0001 per share 03/31/2026 0001650648 4D Molecular Therapeutics, Inc. 35104E100 5858 HORTON STREET #455 EMERYVILLE CA 94608 Rule 13d-1(c) BIOTECHNOLOGY VALUE FUND L P a DE 0.00 3907517.00 0.00 3907517.00 3907517.00 N 7.3 PN BVF I GP LLC a DE 0.00 3907517.00 0.00 3907517.00 3907517.00 N 7.3 OO BIOTECHNOLOGY VALUE FUND II LP a DE 0.00 1093101.00 0.00 1093101.00 1093101.00 N 2.1 PN BVF II GP LLC a DE 0.00 1093101.00 0.00 1093101.00 1093101.00 N 2.1 OO Biotechnology Value Trading Fund OS LP a E9 0.00 289025.00 0.00 289025.00 289025.00 N 0.6 PN BVF Partners OS Ltd. a E9 0.00 289025.00 0.00 289025.00 289025.00 N 0.6 CO BVF GP HOLDINGS LLC a DE 0.00 5000618.00 0.00 5000618.00 5000618.00 N 9.3 OO BVF PARTNERS L P/IL a DE 0.00 5346519.00 0.00 5346519.00 5346519.00 N 9.99 IA PN BVF INC/IL a DE 0.00 5346519.00 0.00 5346519.00 5346519.00 N 9.99 CO LAMPERT MARK N a X1 0.00 5346519.00 0.00 5346519.00 5346519.00 N 9.99 IN 4D Molecular Therapeutics, Inc. 5858 Horton Street #455, Emeryville, CA 94608 Biotechnology Value Fund, L.P. ("BVF") BVF I GP LLC ("BVF GP") Biotechnology Value Fund II, L.P. ("BVF2") BVF II GP LLC ("BVF2 GP") Biotechnology Value Trading Fund OS LP ("Trading Fund OS") BVF Partners OS Ltd. ("Partners OS") BVF GP Holdings LLC ("BVF GPH") BVF Partners L.P. ("Partners") BVF Inc. Mark N. Lampert ("Mr. Lampert") Each of the foregoing is referred to as a "Reporting Person" and collectively as the "Reporting Persons." Biotechnology Value Fund, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF I GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Fund II, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF II GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Trading Fund OS LP PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF Partners OS Ltd. PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF GP Holdings LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Partners L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Inc. 44 Montgomery St., 40th Floor San Francisco, California 94104 Mark N. Lampert 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Fund, L.P. Delaware BVF I GP LLC Delaware Biotechnology Value Fund II, L.P. Delaware BVF II GP LLC Delaware Biotechnology Value Trading Fund OS LP Cayman Islands BVF Partners OS Ltd. Cayman Islands BVF GP Holdings LLC Delaware BVF Partners L.P. Delaware BVF Inc. Delaware Mark N. Lampert United States Y As of the close of business on March 31, 2026, the Reporting Persons and a certain Partners managed account (the "Partners Managed Account") held certain Pre-Funded Warrants (the "Pre-Funded Warrants") exercisable for an aggregate of 8,475,665 Shares. The Pre-Funded Warrants are exercisable at any time at an exercise price of $0.0001 per Share. A holder of Pre-Funded Warrants may not exercise any such Pre-Funded Warrants if upon giving effect to such exercise, it would cause the aggregate number of Shares beneficially owned by the holder (together with affiliates and any other persons whose beneficial ownership Shares would be aggregated for the purposes of Section 13(d) of the Exchange Act) to exceed 9.99% of the total number of then issued and outstanding Shares as determined in accordance with the terms of the Pre-Funded Warrants (the "Pre-Funded Warrants Blocker"). As of the close of business on March 31, 2026, the Pre-Funded Warrants Blocker limits the aggregate exercise of the Pre-Funded Warrants held by the Reporting Persons and the Partners Managed Account to 2,467,230 out of the 8,475,665 Shares underlying the Pre-Funded Warrants held by them. As of the close of business on March 31, 2026, (i) BVF beneficially owned 3,907,517 Shares, including 2,467,230 Shares underlying certain Pre-Funded Warrants held by it and excluding 2,165,390 Shares underlying certain Pre-Funded Warrants held by it, (ii) BVF2 beneficially owned 1,093,101 Shares, excluding 3,319,994 Shares underlying the Pre-Funded Warrants held by it, and (iii) Trading Fund OS beneficially owned 289,025 Shares, excluding 410,036 Shares underlying the Pre-Funded Warrants held by it. BVF GP, as the general partner of BVF, may be deemed to beneficially own the 3,907,517 Shares beneficially owned by BVF. BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 1,093,101 Shares beneficially owned by BVF2. Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 289,025 Shares beneficially owned by Trading Fund OS. BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 5,000,618 Shares beneficially owned in the aggregate by BVF and BVF2. Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own the 5,346,519 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 56,876 Shares held in the Partners Managed Account, which excludes 113,015 Shares underlying the Pre-Funded Warrants held in the Partners Managed Account. BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 5,346,519 Shares beneficially owned by Partners. Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 5,346,519 Shares beneficially owned by BVF Inc. The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any Shares owned by another Reporting Person. BVF GP disclaims beneficial ownership of the Shares beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the Shares beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the Shares beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the Shares beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the Shares beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, and the filing of this statement shall not be construed as an admission that any such person or entity is the beneficial owner of any such securities. The following percentages are based on a denominator that is the sum of: (i) 51,051,487 Shares outstanding as of March 16, 2026, as disclosed in the Issuer's Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 18, 2026, and (ii) 2,467,230 Shares underlying certain Pre-Funded Warrants held by the Reporting Persons, as applicable. As of the close of business on March 31, 2026, (i) BVF beneficially owned approximately 7.3% of the outstanding Shares, (ii) BVF2 beneficially owned approximately 2.1% of the outstanding Shares, (iii) Trading Fund OS beneficially owned less than 1% of the outstanding Shares, (iv) BVF GP may be deemed to beneficially own approximately 7.3% of the outstanding Shares, (v) BVF2 GP may be deemed to beneficially own approximately 2.1% of the outstanding Shares, (vi) Partners OS may be deemed to beneficially own less than 1% of the outstanding Shares, (vii) BVF GPH may be deemed to beneficially own approximately 9.3% of the outstanding Shares and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 9.99% of the outstanding Shares (less than 1% of the outstanding Shares are held in the Partners Managed Account). See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. Y N BVF GP, BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF. BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF2. Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by Trading Fund OS and held in the Partners Managed Account. Y N See Exhibit 99.1 to the Schedule 13G filed with the Securities and Exchange Commission on July 6, 2021. 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. BIOTECHNOLOGY VALUE FUND L P /s/ Mark N. Lampert 05/15/2026 BVF I GP LLC /s/ Mark N. Lampert 05/15/2026 BIOTECHNOLOGY VALUE FUND II LP /s/ Mark N. Lampert 05/15/2026 BVF II GP LLC /s/ Mark N. Lampert 05/15/2026 Biotechnology Value Trading Fund OS LP /s/ Mark N. Lampert 05/15/2026 BVF Partners OS Ltd. /s/ Mark N. Lampert 05/15/2026 BVF GP HOLDINGS LLC /s/ Mark N. Lampert 05/15/2026 BVF PARTNERS L P/IL /s/ Mark N. Lampert 05/15/2026 BVF INC/IL /s/ Mark N. Lampert 05/15/2026 LAMPERT MARK N /s/ Mark N. Lampert 05/15/2026