Mark Simon - 09 Jun 2026 Form 4 Insider Report for Cabaletta Bio, Inc. (CABA)

Reporting relationship: Director
Issuer ticker: CABA
Reported as of: 09 Jun 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 10 Jun 2026, 18:59:48 UTC
Prior SEC filing: 21 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Michael Gerard, Attorney-in-Fact

Key filing fact

Mark Simon filed Form 4 for Cabaletta Bio, Inc. (CABA) on 10 Jun 2026.

Key facts

This page summarizes Mark Simon's Form 4 filing for Cabaletta Bio, Inc. (CABA).
1 reported transaction and 1 derivative row are listed below.
Accepted by SEC: 10 Jun 2026, 18:59.

Change

Previous filing in this sequence was filed on 21 Jan 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001400717 Primary reporting owner

Simon Mark

Relationship: Director
Address: C/O CABALETTA BIO, INC., 2929 ARCH STREET, SUITE 600, PHILADELPHIA
Signature: /s/ Michael Gerard, Attorney-in-Fact
Signature date: 10 Jun 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CABA transaction Derivative

Stock Option (Right to Buy)

Award

Transaction value
Shares: +22,000
Change %
Price: $0.000000^*
Shares after: 22,000
Date: 09 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 22,000
Exercise price: $3.22
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

We use cookies and similar technologies to provide certain features, enhance the user experience and, if you allow them, measure engagement and deliver advertising. Analytics and marketing storage stay off until you grant consent. By clicking on "Agree and continue", you declare your consent to the use of the selected optional cookies. to update or revoke optional consent for future visits. For more information, see our Privacy Policy .