[SCHEDULE 13G/A] Compass Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

RTW Investments, LP and Roderick Wong filed an amended Schedule 13G reporting beneficial ownership of 9,474,397 Ordinary Shares of Compass Therapeutics, Inc. (CUSIP 20451W101). The filing states the reported position represents approximately 9.99% of the class when assuming exercise of warrants to purchase 1,252,468 shares and using 93,586,348 shares outstanding as of June 30, 2025. The Reporting Persons disclose no sole voting or dispositive power and share voting and dispositive power over the reported shares.

The filing notes the RTW Funds have rights to receive dividends or proceeds and identifies RTW Master Fund, Ltd. as holding rights to more than 5% of the reported shares. Issuer and filer addresses are provided in the filing.

Positive

• Material disclosed stake: Reporting Persons beneficially own 9,474,397 shares, a large institutional position (~9.99% after warrant assumptions).
• Warrant exercise cap disclosed: Warrants of 1,252,468 shares cannot be exercised to exceed 9.99%, providing clarity on maximum potential ownership.

Negative

• Inconsistent percentage reporting: the cover page lists 9.9% while Item 4 calculates 9.99% based on 93,586,348 outstanding shares and warrant assumptions.
• Concentrated exposure through RTW Funds: RTW Master Fund, Ltd. is identified as having rights to dividends or proceeds on more than 5% of the reported shares, indicating concentration of beneficiary rights.

Insights

Financial Analyst

TL;DR: RTW and its CIO disclose a near-10% stake (9,474,397 shares) in Compass Therapeutics, material ownership but limited by warrant exercise caps.

The filing shows RTW Investments, LP and Roderick Wong collectively report shared voting and dispositive power over 9,474,397 shares, calculated as roughly 9.99% of a 93,586,348 share base after assuming exercise of 1,252,468 warrants. This is a material, visible position that market participants will treat as a significant institutional holding. The explicit warrant cap preventing ownership above 9.99% constrains further accumulation and clarifies potential dilution assumptions used to calculate percentage ownership.

Corporate Governance Expert

TL;DR: A concentrated ~9.99% holding is material for governance dynamics; the filing clearly discloses voting/dispositive arrangements and beneficiary rights.

The disclosure specifies no sole voting or dispositive power and shared power for both Reporting Persons, which signals collective control rather than unilateral action. The filing also identifies that RTW Funds (including RTW Master Fund, Ltd.) have rights to dividends or sale proceeds, with RTW Master Fund holding rights to more than 5% of the reported shares. These explicit ownership and beneficiary details are important for board engagement and governance signaling.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Compass Therapeutics, Inc.

(Name of Issuer)

Ordinary Shares, par value GBP 0.008 per share

(Title of Class of Securities)

20451W101

(CUSIP Number)

06/30/2025

(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)

SCHEDULE 13G

CUSIP No. 20451W101

1

Names of Reporting Persons

RTW Investments, 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 9,474,397.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,474,397.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,474,397.00

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)

9.9 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP No. 20451W101

1

Names of Reporting Persons

Roderick Wong

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 9,474,397.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,474,397.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,474,397.00

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)

9.9 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Compass Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 80 GUEST STREET, BOSTON, MA, 02135.
Item 2.
(a)	Name of person filing: This statement is filed by: (i) RTW Investments, LP ("RTW Investments"), a Delaware limited partnership and the investment adviser to certain funds (the "RTW Funds"), with respect to Ordinary Shares, par value GBP 0.008 per share (the "Shares") of COMPASS Pathways plc (the "Company") directly held by the RTW Funds; and (ii) Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, as amended, the beneficial owner of the Shares reported herein.
(b)	Address or principal business office or, if none, residence: The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014.
(c)	Citizenship: RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States.
(d)	Title of class of securities: Ordinary Shares, par value GBP 0.008 per share
(e)	CUSIP No.: 20451W101
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: The information required by Item 4(a) is set forth in Rows 5 - 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The amounts reported herein assume the exercise of warrants held by the Reporting Persons to purchase 1,252,468 Shares (the "Warrants") the maximum amount that may be exercised given the current number of outstanding shares and the shares held by the Reporting Persons. Pursuant to the terms of the Warrants, the Reporting Persons cannot exercise any of the Warrants to the extent the Reporting Persons would beneficially own, after any such exercise, more than 9.99% of the outstanding Shares. The percentages set forth in Row 11 of the cover pages are calculated based upon 93,586,348 Shares outstanding as of June 30, 2025 as reported in the Company's Current Report on Form 8-K filed with the Securities and Exchange Commission on July 31, 2025, and assume the exercise of Warrants held by the Reporting Persons to purchase 1,252,468 Shares.
(b)	Percent of class: RTW Investments: 9.99% Dr. Wong: 9.99%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: RTW Investments: 0 Dr. Wong: 0
	(ii) Shared power to vote or to direct the vote: RTW Investments: 9,474,397 Shares Dr. Wong: 9,474,397 Shares
	(iii) Sole power to dispose or to direct the disposition of: RTW Investments: 0 Dr. Wong: 0
	(iv) Shared power to dispose or to direct the disposition of: RTW Investments: 9,474,397 Shares Dr. Wong: 9,474,397 Shares
Item 5.	Ownership of 5 Percent or Less of a Class.
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. See Item 2. The RTW 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 reported herein. RTW Master Fund, Ltd., an RTW Fund, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of more than 5% of the Shares reported herein.
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.

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.

RTW Investments, LP

Signature:	/s/ Roderick Wong, M.D.
Name/Title:	Roderick Wong, M.D., Managing Partner
Date:	08/14/2025

Roderick Wong

Signature:	s/ Roderick Wong, M.D.
Name/Title:	Roderick Wong, M.D.
Date:	08/14/2025

FAQ

Who filed the Schedule 13G/A for Compass Therapeutics (CMPX)?

The statement was filed by RTW Investments, LP and Roderick Wong, M.D. as reporting persons.

How many Compass Therapeutics shares does RTW report owning?

The filing reports beneficial ownership of 9,474,397 Ordinary Shares.

What percent of CMPX does the reported position represent?

Item 4 states approximately 9.99% based on 93,586,348 shares outstanding as of June 30, 2025, assuming exercise of certain warrants.

Are there warrants or other instruments included in the ownership calculation?

Yes. The filing assumes exercise of warrants to purchase 1,252,468 shares and notes those warrants cannot be exercised to exceed 9.99% ownership.

Does any RTW fund have rights to proceeds or dividends from the reported shares?

Yes. The RTW Funds have rights to receive dividends or proceeds, and RTW Master Fund, Ltd. has rights to more than 5% of the reported shares.

When did the event requiring this filing occur and when was the statement signed?

The date of the event is listed as 06/30/2025 and the filing signatures are dated 08/14/2025.