Caribou Biosciences, Inc. — Director's Dealing 2021

Oct 13, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Caribou Biosciences, Inc. (CRBU)
CIK: 0001619856
Period of Report: 2021-10-12

Reporting Person: Kanner Steven (Chief Scientific Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-10-12	Common Stock	P	99548	$1.81	Acquired	199719	Direct
2021-10-12	Common Stock	P	698	$1.81	Acquired	200417	Direct
2021-10-12	Common Stock	P	14614	$2.69	Acquired	215031	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-10-12	Option to purchase Common Stock	$1.81	X	99548	Disposed	2027-07-11	Common Stock (99548)	Direct
2021-10-12	Option to purchase Common Stock	$1.81	X	698	Disposed	2028-03-07	Common Stock (698)	Direct
2021-10-12	Option to purchase Common Stock	$2.69	X	14614	Disposed	2029-09-30	Common Stock (14614)	Direct

Footnotes

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 22, 2021.

F3: This option became fully exercisable on June 30, 2021.

F4: 1/4th of the shares subject to this option vested on October 1, 2020 and an additional 1/48th of the aggregate number of shares subject to the option have vested or will vest on the corresponding day of each month thereafter, subject to the reporting person's continued services to the Issuer through the applicable vesting dates.