Biotechnology Value Fund and affiliated reporting persons filed an amended Schedule 13G/A disclosing shared beneficial ownership in Monte Rosa Therapeutics common stock. As of March 31, 2026, BVF directly held 2,716,569 shares (approximately 3.4%) and BVF II held 1,986,984 shares (approximately 2.5%), with aggregate attributable positions reported up to 5,085,886 shares (approximately 6.3%) under certain entities. The filing states 80,015,667 Shares outstanding as of March 2, 2026 was used to compute percentages and describes 625,000 shares underlying pre-funded warrants exercisable at $0.0001 per share, subject to a 9.99% exercise blocker.
Positive
None.
Negative
None.
Insights
Group discloses passive/shared holdings and pre-funded warrants with a 9.99% blocker.
The Schedule 13G/A lists shared voting and dispositive power across multiple BVF entities, showing 2,716,569 and 1,986,984 shares held by BVF and BVF II respectively, with aggregate attribution of 5,085,886 shares. The filing ties percentages to the issuer's disclosed March 2, 2026 outstanding share count of 80,015,667.
Dependencies include the continued applicability of the Pre-Funded Warrants Blocker (9.99%) and entity disclaimers of beneficial ownership. Subsequent filings or exercises may update positions; timing of any exercise activity is not specified in the provided excerpt.
Key Figures
Shares outstanding used:80,015,667 sharesBVF beneficial ownership:2,716,569 sharesBVF II beneficial ownership:1,986,984 shares+4 more
7 metrics
Shares outstanding used80,015,667 sharesas of <date>March 2, 2026</date>
BVF beneficial ownership2,716,569 sharesas of <date>March 31, 2026</date>
BVF II beneficial ownership1,986,984 sharesas of <date>March 31, 2026</date>
Aggregate attributable shares5,085,886 sharesaggregate across reporting persons
Pre-Funded Warrants exercisable625,000 sharesaggregate exercisable into common stock
Pre-Funded Warrant exercise price$0.0001 per shareexercise price for pre-funded warrants
Pre-Funded Warrants Blocker9.99%ownership and voting blocker upon exercise
"The Pre-Funded Warrants are exercisable for an aggregate of 625,000 Shares"
Pre-funded warrants are financial instruments that give investors the right to purchase a company's stock at a set price, but with most or all of the purchase price paid upfront. They function like a coupon or gift card for stock, allowing investors to buy shares later at a fixed price, which can be beneficial if they want to avoid future price increases. This makes them important for investors seeking flexibility and certainty in their investment plans.
Beneficial ownershipregulatory
"BVF beneficially owned 2,716,569 Shares, including 333,837 Shares underlying the Pre-Funded Warrants"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
Dispositive powerfinancial
"Shared Dispositive Power 2,716,569.00"
Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.
9.99% Blockerregulatory
"will not be entitled to exercise any portion ... to exceed 9.99% of the number of Shares outstanding"
What stake does Biotechnology Value Fund (GLUE) report in Monte Rosa Therapeutics?
BVF reports beneficial ownership of 2,716,569 shares, about 3.4% of the class based on 80,015,667 Shares outstanding as of March 2, 2026. The figure includes 333,837 shares underlying pre-funded warrants.
How many shares do BVF II and Trading Fund OS report owning in GLUE?
BVF II reports 1,986,984 shares (about 2.5%) and Trading Fund OS reports 306,361 shares (less than 1%), each including shares underlying pre-funded warrants as disclosed on March 31, 2026.
What are the terms of the pre-funded warrants disclosed in the filing?
The pre-funded warrants are exercisable into an aggregate of 625,000 shares, exercisable at $0.0001 per share with no expiration and subject to a 9.99% beneficial ownership/voting blocker, per the filing as of March 31, 2026.
Why do multiple BVF entities show overlapping ownership percentages in the Schedule 13G/A?
Multiple affiliated entities are listed because shared voting and dispositive powers are allocated across BVF, general partners, and manager entities; aggregate attribution results in higher combined percentages reported for certain holding entities.
Does the filing state who receives proceeds if any shares are sold?
The filing does not assign proceeds to the issuer; it describes beneficial ownership across reporting persons and a Partners Managed Account but does not specify cash‑flow recipients for any future sales in the provided excerpt.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 3)
Monte Rosa Therapeutics, Inc.
(Name of Issuer)
Common Stock, $0.0001 par value per share
(Title of Class of Securities)
61225M102
(CUSIP Number)
03/31/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BIOTECHNOLOGY VALUE FUND L P
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
2,716,569.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,716,569.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,716,569.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
3.4 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF I GP LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
2,716,569.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,716,569.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,716,569.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
3.4 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BIOTECHNOLOGY VALUE FUND II LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
1,986,984.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,986,984.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,986,984.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
2.5 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF II GP LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
1,986,984.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,986,984.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,986,984.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
2.5 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
Biotechnology Value Trading Fund OS LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
306,361.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
306,361.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
306,361.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0.4 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF Partners OS Ltd.
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
306,361.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
306,361.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
306,361.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0.4 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF GP HOLDINGS LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
4,703,553.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
4,703,553.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,703,553.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.8 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF PARTNERS L P/IL
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,085,886.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,085,886.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,085,886.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
6.3 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
BVF INC/IL
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,085,886.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,085,886.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,085,886.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
6.3 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP Number(s):
61225M102
1
Names of Reporting Persons
LAMPERT MARK N
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,085,886.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,085,886.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,085,886.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
6.3 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Monte Rosa Therapeutics, Inc.
(b)
Address of issuer's principal executive offices:
Item 2.
(a)
Name of person filing:
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."
(b)
Address or principal business office or, if none, residence:
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
(c)
Citizenship:
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
(d)
Title of class of securities:
Common Stock, $0.0001 par value per share
(e)
CUSIP No.:
61225M102
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
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 625,000 Shares. The Pre-Funded Warrants are exercisable at any time at an exercise price of $0.0001 per Share and do not expire. A holder of Pre-Funded Warrants will not be entitled to exercise any portion of such Pre-Funded Warrants that, upon giving effect to such exercise, would result in: (i) the aggregate number of Shares beneficially owned by such holder (together with its affiliates) to exceed 9.99% of the number of Shares outstanding immediately after giving effect to the exercise, or (ii) the combined voting power of the Issuer's securities beneficially owned by such holder (together with its affiliates) to exceed 9.99% of the combined voting power of all of the Issuer's securities then outstanding immediately after giving effect to the exercise (the "Pre-Funded Warrants Blocker"). As of the close of business on March 31, 2026, the Pre-Funded Warrants Blocker did not limit the exercise of any of the Pre-Funded Warrants held by the Reporting Persons and the Partners Managed Account.
As of the close of business on March 31, 2026, (i) BVF beneficially owned 2,716,569 Shares, including 333,837 Shares underlying the Pre-Funded Warrants held by it, (ii) BVF2 beneficially owned 1,986,984 Shares, including 244,178 Shares underlying the Pre-Funded Warrants held by it, and (iii) Trading Fund OS beneficially owned 306,361 Shares, including 37,649 Shares underlying the Pre-Funded Warrants held by it.
BVF GP, as the general partner of BVF, may be deemed to beneficially own the 2,716,569 Shares beneficially owned by BVF.
BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 1,986,984 Shares beneficially owned by BVF2.
Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 306,361 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 4,703,553 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 5,085,886 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 75,972 Shares held in the Partners Managed Account, which includes 9,336 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 5,085,886 Shares beneficially owned by Partners.
Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 5,085,886 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.
(b)
Percent of class:
The following percentages are based upon a denominator that is the sum of (i) 80,015,667 Shares outstanding as of March 2, 2026, as disclosed in the Issuer's Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 17, 2026, and (ii) certain or all of the 625,000 Shares underlying the Pre-Funded Warrants held by the Reporting Persons and the Partners Managed Account, as applicable.
As of the close of business on March 31, 2026, (i) BVF beneficially owned approximately 3.4% of the outstanding Shares, (ii) BVF2 beneficially owned approximately 2.5% 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 3.4% of the outstanding Shares, (v) BVF2 GP may be deemed to beneficially own approximately 2.5% 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 5.8% of the outstanding Shares, and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 6.3% of the outstanding Shares (less than 1% of the outstanding Shares are held in the Partners Managed Account).
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See Cover Pages Items 5-9.
(ii) Shared power to vote or to direct the vote:
See Cover Pages Items 5-9.
(iii) Sole power to dispose or to direct the disposition of:
See Cover Pages Items 5-9.
(iv) Shared power to dispose or to direct the disposition of:
See Cover Pages Items 5-9.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF and 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.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group.
See Exhibit 99.1 to the Schedule 13G filed with the Securities and Exchange Commission on January 31, 2025.
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
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.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
