Nichtberger Steven - 31 Jan 2022 Form 4 Insider Report for Cabaletta Bio, Inc. (CABA)

Role: President & CEO, Director
Signature: By: /s/ Michael Gerard, Attorney-in-Fact
Issuer symbol: CABA
Transactions as of: 31 Jan 2022
Net transactions value: +$50,500
Form type: 4
Filing time: 02 Feb 2022, 15:26:07 UTC
Previous filing: 19 Jan 2022
Next filing: 18 Oct 2022
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CABA	Common Stock	Options Exercise	$50,500	+50,000	+6.4%	$1.01^*	836,483	31 Jan 2022	Direct
holding	CABA	Common Stock						363,000	31 Jan 2022	By 2017 Nichtberger Family Trust	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CABA	Stock Option (Right to Buy)	Options Exercise	$0	-50,000	-18%	$0.000000	229,677	31 Jan 2022	Common Stock	50,000	$1.01	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
F2	On October 29, 2018, the reporting person was granted a stock option to purchase 279,677 shares of common stock. The shares vest and become exercisable over four years, with 25% vested on October 11, 2019, and the remaining shares vesting in 36 equal monthly installments thereafter. On January 31, 2022 the reporting person exercised this option for 50,000 shares.