[SCHEDULE 13G] Q32 Bio Inc. Passive Investment Disclosure (>5%)
Sirenia reports 9.9% stake in Q32 Bio
Sirenia Capital Management and Alex Silverstein report beneficial ownership of Common Stock in Q32 Bio Inc. The filing states a reported position of 2,057,308 shares, representing 9.9% of the class on a fully‑exercised basis subject to a 9.99% blocker.
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Sirenia Capital Management and Alex Silverstein report beneficial ownership of Common Stock in Q32 Bio Inc. The filing states a reported position of 2,057,308 shares, representing 9.9% of the class on a fully‑exercised basis subject to a 9.99% blocker. The percentage calculation uses 14,629,463 shares outstanding as of March 1, 2026. The filing also discloses 1,025,654 shares issuable upon exercise of reported warrants held by the Sirenia Fund and notes the blocker limits exercise to prevent ownership above 9.99%.
Key Figures
Shares reported beneficially owned:2,057,308 sharesPercent of class:9.9%Shares issuable on exercise:1,025,654 shares+2 more
5 metrics
Shares reported beneficially owned2,057,308 sharesReported on cover page for Sirenia/Mr. Silverstein
Percent of class9.9%Calculated based on 14,629,463 shares outstanding as of March 1, 2026
Shares issuable on exercise1,025,654 sharesIssuable upon exercise of Reported Warrants held by the Sirenia Fund
Shares outstanding used14,629,463 sharesOutstanding as of <date>March 1, 2026</date>, per issuer prospectus
CUSIP746964105Q32 Bio Inc. Common Stock CUSIP on cover page
"Includes 1,025,654 shares of Common Stock issuable upon exercise of the Reported Warrants"
9.99% Blockerregulatory
"the Reported Warrants are subject to the 9.99% Blocker"
Beneficial ownershipfinancial
"Amount beneficially owned: The information required by Item 4(a) is set forth"
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.
Joint Filing Agreementlegal
"Sirenia and Mr. Silverstein have entered into a Joint Filing Agreement"
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What stake does Sirenia report in QTTB (Q32 Bio)?
Sirenia reports beneficial ownership of 2,057,308 shares, equal to 9.9% of the class. This percentage assumes the exercise of reported warrants and is calculated using 14,629,463 shares outstanding as of March 1, 2026.
How many shares are issuable on exercise of the reported warrants?
The filing shows 1,025,654 shares issuable upon exercise of the reported warrants. The filing states the warrants are subject to a 9.99% Blocker that limits exercise to avoid exceeding that threshold.
Does Sirenia currently have the right to exercise all reported warrants?
No. The filing explains the reported warrants are subject to a 9.99% Blocker, and Sirenia cannot exercise warrants that would cause beneficial ownership to exceed 9.99% of outstanding shares.
What share count was used to calculate the percentage ownership?
The percentage is calculated using 14,629,463 shares outstanding as of March 1, 2026. That figure is cited from the issuer's prospectus filed March 27, 2026, and underlies the 9.9% calculation.
Who filed the statement for this reported position in QTTB?
The statement was filed jointly by Sirenia Capital Management LP and Alex Silverstein, the managing member of Sirenia Capital's GP, under a Joint Filing Agreement (Exhibit 99.1).
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Q32 Bio Inc.
(Name of Issuer)
Common Stock, par value $0.0001 per share
(Title of Class of Securities)
746964105
(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):
746964105
1
Names of Reporting Persons
Sirenia Capital Management 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
2,057,308.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,057,308.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,057,308.00
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
Comment for Type of Reporting Person: Includes 1,025,654 shares of Common Stock (as defined in Item 2(a)) issuable upon exercise of the Reported Warrants (as defined in Item 4(a)). As more fully described in Item 4, the Reported Warrants are subject to the 9.99% Blocker (as defined in Item 4(a)) and the percentage set forth on row (11) gives effect to the 9.99% Blocker. However, rows (6), (8) and (9) show the number of shares of Common Stock that would be issuable upon the full exercise of the Reported Warrants and does not give effect to the 9.99% Blocker. Therefore, the actual number of shares of Common Stock beneficially owned by such Reporting Person, after giving effect to the 9.99% Blocker, is less than the number of securities reported on rows (6), (8) and (9).
SCHEDULE 13G
CUSIP Number(s):
746964105
1
Names of Reporting Persons
Alex Silverstein
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
2,057,308.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,057,308.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,057,308.00
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
Comment for Type of Reporting Person: Includes 1,025,654 shares of Common Stock issuable upon exercise of the Reported Warrants. As more fully described in Item 4, the Reported Warrants are subject to the 9.99% Blocker and the percentage set forth on row (11) gives effect to the 9.99% Blocker. However, rows (6), (8) and (9) show the number of shares of Common Stock that would be issuable upon the full exercise of the Reported Warrants and does not give effect to the 9.99% Blocker. Therefore, the actual number of shares of Common Stock beneficially owned by such Reporting Person, after giving effect to the 9.99% Blocker, is less than the number of securities reported on rows (6), (8) and (9).
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Q32 Bio Inc.
(b)
Address of issuer's principal executive offices:
830 Winter Street, Waltham, Massachusetts 02451
Item 2.
(a)
Name of person filing:
This statement is filed by:
(i) Sirenia Capital Management LP ("Sirenia") with respect to the common stock, par value $0.0001 per share ("Common Stock"), of Q32 Bio Inc. (the "Issuer") held by, and issuable upon exercise of the Reported Warrants held by SILV Fund, Ltd. (the "Sirenia Fund"), an investment fund it manages; and
(ii) Alex Silverstein ("Mr. Silverstein"), the managing member of Sirenia Capital Management GP LLC, the general partner of Sirenia, with respect to the Common Stock held by, and issuable upon exercise of Reported Warrants held by, the Sirenia Fund.
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, the beneficial owner of the securities reported herein.
Sirenia and Mr. Silverstein have entered into a Joint Filing Agreement, a copy of which is filed with this Schedule 13G as Exhibit 99.1, pursuant to which they have agreed to file this Schedule 13G jointly in accordance with the provisions of Rule 13d-1(k) of the Securities Exchange Act of 1934 (the "Act").
(b)
Address or principal business office or, if none, residence:
The address of the principal business office of Sirenia and Mr. Silverstein is 1674 Meridian Avenue, Suite 320, Miami Beach, FL 33139.
(c)
Citizenship:
Sirenia is a Delaware limited partnership. Mr. Silverstein is a United States citizen.
(d)
Title of class of securities:
Common Stock, par value $0.0001 per share
(e)
CUSIP Number(s):
746964105
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 Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 14,629,463 shares of Common Stock outstanding as of March 1, 2026, as reported in the Issuer's Prospectus filed pursuant to Rule 424(b)(5) with the Securities and Exchange Commission on March 27, 2026, and assumes the exercise of the warrants (the "Reported Warrants") held by the Sirenia Fund.
Pursuant to the terms of the Reported Warrants, the Reporting Persons cannot exercise any of the Reported Warrants to the extent the Reporting Persons would beneficially own, after any such exercise, more than 9.99% of the outstanding shares of Common Stock (the "9.99% Blocker") and the percentage set forth in Row (11) of the cover page for each of the Reporting Persons gives effect to the 9.99% Blocker. Consequently, at this time, the Reporting Persons are not able to exercise all of such Reported Warrants due to the 9.99% Blocker.
(b)
Percent of class:
9.9%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(ii) Shared power to vote or to direct the vote:
The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iii) Sole power to dispose or to direct the disposition of:
The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iv) Shared power to dispose or to direct the disposition of:
The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
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.
See Item 2(a). The Sirenia 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 percent of the outstanding Common Stock.
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.
Sirenia Capital Management LP
Signature:
/s/ Kolby Loft
Name/Title:
Kolby Loft, General Counsel & Chief Compliance Officer
