Cabaletta CMO buys 8,800 shares at $2.26

Cabaletta Bio Chief Medical Officer David J. Chang reported buying 8,800 shares of Cabaletta Bio common stock on January 21, 2026.

Rhea-AI Filing Summary

Cabaletta Bio Chief Medical Officer David J. Chang reported buying 8,800 shares of Cabaletta Bio common stock on January 21, 2026. The purchase was made in an open-market transaction coded “P” at a price of $2.26 per share. After this transaction, he directly owns 8,800 common shares of the company.

Insider Trade Summary

Net Buyer: 8,800 shares

Net Buy 1 txn

Insider Chang David J.

Role Chief Medical Officer

Bought 8,800 shs ($20K)

Type	Security	Shares	Price	Value
Purchase	Common Stock	8,800	$2.26	$20K

Holdings After Transaction: Common Stock — 8,800 shares (Direct)

FAQ

What insider transaction did Cabaletta Bio (CABA) report for David J. Chang?

Cabaletta Bio’s Chief Medical Officer, David J. Chang, reported an open-market purchase of 8,800 shares of common stock on January 21, 2026.

At what price did the Cabaletta Bio (CABA) CMO buy shares?

David J. Chang bought Cabaletta Bio common stock at a price of $2.26 per share in the reported transaction.

How many Cabaletta Bio (CABA) shares does David J. Chang own after the transaction?

Following the reported purchase, David J. Chang directly owns 8,800 shares of Cabaletta Bio common stock.

What is the role of David J. Chang at Cabaletta Bio (CABA)?

David J. Chang serves as Chief Medical Officer of Cabaletta Bio, according to the insider ownership filing.

Was the Cabaletta Bio (CABA) insider transaction direct or indirect ownership?

The filing shows the ownership form as direct (D), meaning the 8,800 shares are held directly by David J. Chang.

What type of security did the Cabaletta Bio (CABA) insider purchase?

The transaction involved common stock of Cabaletta Bio; no derivative securities were reported in the filing.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 01/21/2026 - 06:56 PM Learn about SEC filing dates

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
Estimated average burden
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^*

Chang David J.

(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 Medical Officer

3. Date of Earliest Transaction (Month/Day/Year)
01/21/2026

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
Common Stock	01/21/2026		P		8,800	A	$2.26	8,800	D

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

Explanation of Responses:

	By: /s/ Michael Gerard, as Attorney-in-Fact	01/21/2026
	** 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.