Cabaletta Bio, Inc. reports that Cormorant Asset Management and Bihua Chen hold 10,500,000 shares of Common Stock, representing 9.03% of the class. The holdings reflect Common Stock issuable upon exercise of warrants; the Warrants are exercisable for up to 5,000,000 shares. Shares outstanding were 111,322,671 as of March 19, 2026, per the company’s Form 10-K dated March 23, 2026.
The filing states the reported shares are held by the Cormorant Funds with shared voting and dispositive power of 10,500,000 and identifies Cormorant Global Healthcare Master Fund, LP as having economic rights to more than 5% of the shares.
Positive
None.
Negative
None.
Insights
Large passive stake disclosed via Schedule 13G/A; holdings are warrant‑linked.
The report shows 10,500,000 shares (9.03%) held by Cormorant Funds, with shared voting and dispositive power. The filing clarifies these holdings reflect common stock issuable upon exercise of warrants and cites a 5,000,000‑share warrant cap.
Implications depend on whether warrants are exercised; timing and cash‑flow treatment are not stated in this excerpt. Subsequent filings would show any exercises or conversions.
Shared control structure and beneficial‑owner disclosure are explicit; a >5% holder is named.
The Schedule 13G/A attributes shared voting and dispositive power to the Reporting Persons and identifies Cormorant Global Healthcare Master Fund, LP as holding over 5% of economic rights. The filing includes the reporting person addresses and citizenship.
Because the statement is on a 13G/A, it characterizes passive ownership; any change to active intent would require different disclosure filings.
Key Figures
Beneficially owned:10,500,000 sharesPercent of class:9.03%Shares outstanding:111,322,671 shares+1 more
4 metrics
Beneficially owned10,500,000 sharesAmount beneficially owned reported in Schedule 13G/A
Percent of class9.03%Calculated using shares outstanding as of March 19, 2026
Shares outstanding111,322,671 sharesOutstanding shares as of March 19, 2026 (Form 10‑K cited Mar 23, 2026)
Warrants exercisable5,000,000 sharesWarrants exercisable for up to this number, per the filing
"The Reporting Persons' holdings reported herein reflect shares issuable upon the exercise of warrants"
Warrants are special documents that give you the right to buy a company's stock at a set price before a certain date. They are often used as a way for companies to attract investors or raise money, and their value can increase if the company's stock price goes up.
Shared Dispositive Powerregulatory
"Shared Dispositive Power 10,500,000.00"
Schedule 13G/Aregulatory
"This statement is filed by Cormorant Asset Management, LP ... Schedule 13G/A amendment"
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.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 3)
Cabaletta Bio, Inc.
(Name of Issuer)
Common Stock, par value $0.00001 per share
(Title of Class of Securities)
12674W109
(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):
12674W109
1
Names of Reporting Persons
Cormorant Asset 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
10,500,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
10,500,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
10,500,000.00
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)
9.03 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
12674W109
1
Names of Reporting Persons
Bihua Chen
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
10,500,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
10,500,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
10,500,000.00
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)
9.03 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Cabaletta Bio, Inc.
(b)
Address of issuer's principal executive offices:
2929 Arch Street, Suite 600, Philadelphia, PA 19104
Item 2.
(a)
Name of person filing:
Cormorant Asset Management, LP
Bihua Chen
This statement is filed by (i) Cormorant Asset Management, LP, a Delaware limited partnership, and the investment adviser to certain funds (the "Cormorant Funds"), with respect to the shares directly held by the Cormorant Funds and (ii) Bihua Chen with respect to the shares directly held by the Cormorant 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 Act, the beneficial owner of the shares reported herein.
(b)
Address or principal business office or, if none, residence:
200 Clarendon Street, 52nd Floor
Boston, MA 02116
(c)
Citizenship:
Cormorant Asset Management, LP - Delaware
Bihua Chen - United States
(d)
Title of class of securities:
Common Stock, par value $0.00001 per share
(e)
CUSIP No.:
12674W109
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:
10,500,000
(b)
Percent of class:
9.03%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
0
(ii) Shared power to vote or to direct the vote:
10,500,000
(iii) Sole power to dispose or to direct the disposition of:
0
(iv) Shared power to dispose or to direct the disposition of:
10,500,000
The Reporting Persons' holdings reported herein reflect shares of common stock of the Issuer ("Common Stock") issuable upon the exercise of warrants (the "Warrants"). The Warrants are exercisable for up to 5,000,000 shares of Common Stock. The percentages reported herein with respect to the Reporting Persons' holdings are calculated based upon a statement in the Issuer's Annual Report on Form 10-K for the fiscal year ended December 31, 2025, as filed with the Securities and Exchange Commission on March 23, 2026, that there were 111,322,671 shares of Common Stock of the Issuer outstanding as of March 19, 2026.
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. The Cormorant 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. Cormorant Global Healthcare Master Fund, LP, a Cormorant Fund, has the right to receive or the power to direct the receipt of dividends or the proceeds from the sale of more than 5% of the shares.
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.
Cormorant Asset Management, LP
Signature:
/s/ Bihua Chen
Name/Title:
Bihua Chen, Managing Member
Date:
05/15/2026
Bihua Chen
Signature:
/s/ Bihua Chen
Name/Title:
Bihua Chen
Date:
05/15/2026
Exhibit Information
Joint Filing Statement, incorporated by reference to the Joint Filing Statement included with the Schedule 13G filed by the Reporting Persons on August 14, 2025.
Cormorant Asset Management and Bihua Chen report beneficial ownership of 10,500,000 shares, equal to 9.03% of the class, based on 111,322,671 shares outstanding as of March 19, 2026.
Are the reported Cabaletta shares ordinary shares or from warrants?
The filing states the holdings reflect Common Stock issuable upon exercise of warrants. The Warrants are exercisable for up to 5,000,000 shares, per the Schedule 13G/A text.
Does Cormorant have voting control over the reported shares?
The Schedule 13G/A reports shared voting power of 10,500,000 shares and shared dispositive power of 10,500,000 shares, with no sole voting or dispositive power listed.
Which fund holds more than 5% of Cabaletta according to this filing?
Cormorant Global Healthcare Master Fund, LP, a Cormorant Fund, is identified as having the right to receive dividends or proceeds from the sale of more than 5% of the shares reported.
What outstanding share count did the filing use to calculate 9.03%?
The percentage is calculated using 111,322,671 shares outstanding as of March 19, 2026, cited from the company’s Annual Report on Form 10‑K filed March 23, 2026.
