Cabaletta Bio (CABA) CFO awarded 225,000-share stock option grant

Rhea-AI Filing Summary

Cabaletta Bio, Inc. reported that its Chief Financial Officer, Anup Marda, received a grant of stock options covering 225,000 shares of common stock. The options were acquired as a grant, with 25% scheduled to vest and become exercisable on March 1, 2027, and the remaining 75% vesting in twelve substantially equal quarterly installments thereafter, conditioned on his continued service with the company on each vesting date.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Marda Anup

(Last) (First) (Middle)

C/O CABALETTA BIO, INC.

2929 ARCH STREET, SUITE 600

(Street)

PHILADELPHIA PA 19104

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cabaletta Bio, Inc. [ CABA ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$3.3	03/02/2026		A		225,000		(1)	03/01/2036	Common Stock	225,000	$0	225,000	D

Explanation of Responses:

1. 25% of the shares underlying this option shall vest and become exercisable on March 1, 2027, with the remainder vesting in twelve substantially equal quarterly installments thereafter, subject to the reporting person's continued service on each such vesting date.

	By: /s/ Michael Gerard, as Attorney-in-Fact	03/02/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Cabaletta Bio (CABA) disclose for Anup Marda?

Cabaletta Bio disclosed that CFO Anup Marda received a grant of stock options for 225,000 shares. These options represent a compensation award and were reported as an acquisition rather than an open-market purchase or sale of Cabaletta Bio common stock.

How many stock options did the Cabaletta Bio (CABA) CFO receive?

Cabaletta Bio’s CFO received 225,000 stock options as a grant. This entire amount was reported as the total derivative securities held following the transaction, reflecting a new equity-based compensation award tied to future vesting and exercisability conditions.

When do the newly granted Cabaletta Bio (CABA) options start vesting?

The granted options begin vesting on March 1, 2027, when 25% of the shares underlying the option vest and become exercisable. The remaining portion vests in twelve substantially equal quarterly installments, assuming the CFO continues to serve the company on each vesting date.

What is the vesting schedule for the Cabaletta Bio (CABA) CFO’s option grant?

The vesting schedule provides that 25% vests on March 1, 2027, with the remaining 75% vesting in twelve substantially equal quarterly installments. Each installment requires the CFO’s continued service with Cabaletta Bio on the applicable vesting date to become exercisable.

Was the Cabaletta Bio (CABA) CFO’s transaction a purchase or a grant?

The transaction was reported as a grant or award acquisition of stock options, not an open-market purchase. It is coded as a derivative acquisition (Code “A”) and reflects equity compensation rather than a discretionary buy or sell of existing Cabaletta Bio shares.

How many derivative securities does the Cabaletta Bio (CABA) CFO hold after this grant?

Following the grant, the CFO is reported as holding 225,000 derivative securities in the form of stock options. This figure equals the size of the new award and represents his total reported stock option holdings from this specific grant after the transaction.