Ryan Fischesser - Oct 11, 2021 Form 4 Insider Report for Caribou Biosciences, Inc. (CRBU)

Role: VP of Finance and Controller
Signature: /s/ Barbara G. McClung, as attorney-in-fact
Stock symbol: CRBU
Transactions as of: Oct 11, 2021
Transactions value $: $4,697
Form type: 4
Date filed: 10/12/2021, 07:33 PM
Previous filing: Jul 23, 2021
Next filing: Dec 21, 2021

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CRBU	Common Stock	Purchase	$4.7K	+1.75K	+1.77%	$2.69	101K	Oct 11, 2021	Direct	F1, F2

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	CRBU	Option to purchase Common Stock	Exercise of in-the-money or at-the-money derivative security	$0	-1.75K	-17.01%	$0.00	8.52K	Oct 11, 2021	Common Stock	1.75K	$2.69	Direct	F2, F3

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

Explanation of Responses:

Id	Content
F1	These shares were acquired pursuant to the exercise of a stock option, as reported in Table II below.
F2	The exercise price for this stock option was incorrectly reported as $2.68 per share on the reporting person's Form 3 filed on July 23, 2021.
F3	The shares subject to this option have vested or will vest in equal monthly installments until the option is fully vested on January 1, 2023, subject to the reporting person's continued service to the Issuer through the applicable vesting dates.