C4 Therapeutics (NASDAQ: CCCC) — Squadron Fund reports 5.55M shares

Rhea-AI Filing Summary

C4 Therapeutics, Inc. Schedule 13G: Squadron Master Fund LP and affiliated filers report beneficial ownership of 5,550,000 shares of common stock, representing 5.0% of the class based on 110,567,222 shares outstanding as of May 1, 2026.

The filing states the holdings reflect shared voting and dispositive power and includes a Rule 13d-4 disclaimer that the adviser and named partners disclaim beneficial ownership.

Key Figures

Reported shares owned: 5,550,000 shares Percent of class: 5.0% Shares outstanding: 110,567,222 shares

3 metrics

Reported shares owned 5,550,000 shares Beneficially owned by Squadron Master Fund LP (filing)

Percent of class 5.0% Calculated using 110,567,222 shares outstanding as of <date>May 1, 2026</date>

Shares outstanding 110,567,222 shares Shares outstanding reported by the issuer as of <date>May 1, 2026</date>

Key Terms

Schedule 13G, Rule 13d-4, Exempt Reporting Adviser

3 terms

Schedule 13G regulatory

"Signed statement titled Schedule 13G reporting beneficial ownership"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

Rule 13d-4 regulatory

"Pursuant to Rule 13d-4, Squadron Capital Management, LLC and Mr. Sesterhenn and Mr. Blank expressly disclaim beneficial ownership"

Exempt Reporting Adviser financial

"Squadron Capital Management, LLC is an investment adviser that is registered as an Exempt Reporting Adviser"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

C4 Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

12529R107

(CUSIP Number)

05/12/2026

(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): 12529R107

1

Names of Reporting Persons

Squadron Master Fund 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 5,550,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,550,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,550,000.00

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)

5.0 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 12529R107

1

Names of Reporting Persons

Squadron Capital Management 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 5,550,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,550,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,550,000.00

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)

5.0 %

12

Type of Reporting Person (See Instructions)

IA, HC

SCHEDULE 13G

CUSIP Number(s): 12529R107

1

Names of Reporting Persons

Matthew Sesterhenn

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 5,550,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,550,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,550,000.00

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)

5.0 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP Number(s): 12529R107

1

Names of Reporting Persons

William Blank

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 5,550,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,550,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,550,000.00

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)

5.0 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: C4 Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 490 ARSENAL WAY, SUITE 120, WATERTOWN, MASSACHUSETTS, 02472.
Item 2.
(a)	Name of person filing: Squadron Master Fund LP Squadron Capital Management, LLC Matthew Sesterhenn William Blank
(b)	Address or principal business office or, if none, residence: Squadron Master Fund LP c/o Squadron Capital Management, LLC 999 Oakmont Plaza Drive, Suite 600 Westmont, IL 60559 Squadron Capital Management, LLC 999 Oakmont Plaza Drive, Suite 600 Westmont, IL 60559 Matthew Sesterhenn c/o Squadron Capital Management, LLC 999 Oakmont Plaza Drive, Suite 600 Westmont, IL 60559 William Blank c/o Squadron Capital Management, LLC 999 Oakmont Plaza Drive, Suite 600 Westmont, IL 60559
(c)	Citizenship: Squadron Master Fund LP - Delaware Squadron Capital Management, LLC - Delaware Matthew Sesterhenn - United States William Blank - United States
(d)	Title of class of securities: Common Stock, $0.0001 par value per share
(e)	CUSIP Number(s): 12529R107
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: Squadron Capital Management, LLC is an investment adviser that is registered as an Exempt Reporting Adviser with the Securities and Exchange Commission. Squadron Capital Management, LLC, which serves as investment adviser to private funds, including but not limited to Squadron Master Fund LP (collectively, the "Funds"), may be deemed to be the beneficial owner of all shares of Common Stock held by the Funds. Mr. Sesterhenn and Mr. Blank, as Partners of Squadron Capital Management, LLC, with the power to exercise investment and voting discretion, may be deemed to be the beneficial owner of all shares of Common Stock held by the Funds. Pursuant to Rule 13d-4 under the Securities Exchange Act of 1934, as amended, Squadron Capital Management, LLC and Mr. Sesterhenn and Mr. Blank expressly disclaim beneficial ownership over any of the securities reported in this statement, and the filing of this statement shall not be construed as an admission that Squadron Capital Management, LLC or Mr. Sesterhenn and Mr. Blank are the beneficial owner of any of the securities reported herein. Squadron Master Fund LP - 5,550,000 shares Squadron Capital Management, LLC - 5,550,000 shares Matthew Sesterhenn - 5,550,000 shares William Blank - 5,550,000 shares
(b)	Percent of class: Ownership percentage is based on 110,567,222 shares of common stock outstanding, par value $0.0001 per share, as of May 1, 2026, as reported by the Issuer on Form 10-K filed with the Securities and Exchange Commission on May 12, 2026. Squadron Master Fund LP - 5.0% Squadron Capital Management, LLC - 5.0% Matthew Sesterhenn - 5.0% William Blank - 5.0%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Squadron Master Fund LP - 0 Squadron Capital Management, LLC - 0 Matthew Sesterhenn - 0 William Blank - 0
	(ii) Shared power to vote or to direct the vote: Squadron Master Fund LP - 5,550,000 shares Squadron Capital Management, LLC - 5,550,000 shares Matthew Sesterhenn - 5,550,000 shares William Blank - 5,550,000 shares
	(iii) Sole power to dispose or to direct the disposition of: Squadron Master Fund LP - 0 Squadron Capital Management, LLC - 0 Matthew Sesterhenn - 0 William Blank - 0
	(iv) Shared power to dispose or to direct the disposition of: Squadron Master Fund LP - 5,550,000 shares Squadron Capital Management, LLC - 5,550,000 shares Matthew Sesterhenn - 5,550,000 shares William Blank - 5,550,000 shares
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. The Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock covered by this Statement.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Notes above.
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 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.

Squadron Master Fund LP

Signature:	/s/ Matthew Sesterhenn
Name/Title:	Partner, Squadron Partners LLC, its General Partner
Date:	05/19/2026

Squadron Capital Management LLC

Signature:	/s/ Matthew Sesterhenn
Name/Title:	Partner
Date:	05/19/2026

Matthew Sesterhenn

Signature:	/s/ Matthew Sesterhenn
Name/Title:	Matthew Sesterhenn
Date:	05/19/2026

William Blank

Signature:	/s/ William Blank
Name/Title:	William Blank
Date:	05/19/2026

FAQ

How many C4 Therapeutics (CCCC) shares does Squadron Master Fund report?

They report owning 5,550,000 shares of common stock. The filing states this equals 5.0% of the class using 110,567,222 shares outstanding as of May 1, 2026 as the issuer-provided base.

Does the Schedule 13G filing show voting or dispositive power for these shares?

Yes. The filing reports shared voting power and shared dispositive power over the 5,550,000 shares. It attributes those powers to the Funds and to Squadron Capital Management partners.

Who are the named filers on the Schedule 13G for C4 Therapeutics?

The filing lists Squadron Master Fund LP, Squadron Capital Management, LLC, and partners Matthew Sesterhenn and William Blank. All four are reported as holding 5,550,000 shares each for reporting purposes.

What is the significance of the Rule 13d-4 disclaimer in this filing?

The disclaimer states the adviser and partners expressly disclaim beneficial ownership under Rule 13d-4. It signals the filers assert reporting obligations without admitting direct beneficial ownership of the securities.