T. Rowe Price reports 8.86M-share stake in Monte Rosa Therapeutics (GLUE)

Rhea-AI Filing Summary

Monte Rosa Therapeutics received an amended ownership filing showing T. Rowe Price Associates, Inc. beneficially owns 8,861,282 shares of Common Stock, representing 10.5% of the class as of 06/30/2026. The filing lists sole voting power for 8,856,521 shares and sole dispositive power for 8,861,282.

Insights

Institutional Ownership Analyst

Large passive stake: 10.5% reported by T. Rowe Price as of 06/30/2026.

T. Rowe Price Associates is reported to beneficially own 8,861,282 shares, equal to 10.5% of the outstanding common stock. The filing quantifies both voting and dispositive powers, indicating substantive control over disposition decisions.

Timing is tied to 06/30/2026; subsequent trading or amendments could change this stake. Cash‑flow treatment and whether shares are held across multiple funds are not stated in the excerpt.

Securities Compliance Counsel

Amendment clarifies holdings and voting/dispositive powers; standard Schedule 13G/A language included.

The filing contains the required disclosure items: issuer name, filer name and address, amount beneficially owned (8,861,282), and percentage of class (10.5%) as of 06/30/2026. It includes a statement denying admission of beneficial ownership consistent with some advisory‑firm filings.

Legal qualifiers and signature are present. Investors should note this is a disclosure of holdings, not a statement of intent to acquire or dispose.

Key Figures

Amount beneficially owned: 8,861,282 shares Percent of class: 10.5% Sole voting power: 8,856,521 shares +1 more

4 metrics

Amount beneficially owned 8,861,282 shares as of 06/30/2026

Percent of class 10.5% percentage of common stock

Sole voting power 8,856,521 shares shares with sole voting power

Sole dispositive power 8,861,282 shares shares with sole dispositive power

Key Terms

Schedule 13G/A, Beneficial ownership, Sole dispositive power

3 terms

Schedule 13G/A regulatory

"Amendment No. 7 ) MONTE ROSA THERAPEUTICS INC COMMON STOCK"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficial ownership financial

"Item 4. | Ownership (a) | Amount beneficially owned: 8861282"

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.

Sole dispositive power regulatory

"(iii) Sole power to dispose or to direct the disposition of: 8861282"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 07/08/2026 - 11:29 AM Accepted by SEC EDGAR 07/08/2026 - 11:28 AM Learn about SEC filing dates

FAQ

What stake does T. Rowe Price report in MONTE ROSA THERAPEUTICS (GLUE)?

T. Rowe Price reports beneficial ownership of 8,861,282 shares, representing 10.5% of the class as of 06/30/2026. The filing lists sole voting power for 8,856,521 shares and sole dispositive power for 8,861,282 shares.

Does the Schedule 13G/A indicate T. Rowe Price will sell or buy GLUE shares?

No; the filing discloses holdings and voting/dispositive powers but does not state any planned purchases or sales. It simply reports beneficial ownership of 8,861,282 shares as of 06/30/2026.

What powers does T. Rowe Price claim over the GLUE shares it reports?

The filing shows sole power to vote over 8,856,521 shares and sole dispositive power over 8,861,282 shares, indicating control of voting and disposition for those shares as reported.

When was the ownership information in the amendment effective for GLUE?

The ownership figures are presented as of 06/30/2026 and the amendment was signed on 07/08/2026 by a T. Rowe Price Vice President, per the excerpted filing.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 7)

MONTE ROSA THERAPEUTICS INC

(Name of Issuer)

COMMON STOCK

(Title of Class of Securities)

61225M102

(CUSIP Number)

06/30/2026

(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

T. Rowe Price Associates, Inc.

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

MARYLAND

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 8,856,521.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 8,861,282.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

8,861,282.00

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)

10.5 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: MONTE ROSA THERAPEUTICS INC
(b)	Address of issuer's principal executive offices: 645 SUMMER STREET, SUITE 102, BOSTON, MA, 02210
Item 2.
(a)	Name of person filing: T. Rowe Price Associates, Inc.
(b)	Address or principal business office or, if none, residence: 1307 Point Street, Baltimore, MD 21231
(c)	Citizenship: Maryland
(d)	Title of class of securities: COMMON STOCK
(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: 8861282
(b)	Percent of class: 10.5 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 8856521
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 8861282
	(iv) Shared power to dispose or to direct the disposition of: 0
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.
	Not Applicable
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.
	Not Applicable
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 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. T. Rowe Price Associates, Inc. hereby declares and affirms that the filing of Schedule 13G shall not be construed as an admission that Price Associates is the beneficial owner of the securities referred to, which beneficial ownership is expressly denied.

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.

T. Rowe Price Associates, Inc.

Signature:	Ellen York
Name/Title:	Vice President
Date:	07/08/2026