Ruhi Ahmad Khan - Feb 20, 2025 Form 4 Insider Report for Caribou Biosciences, Inc. (CRBU)

Role: Chief Business Officer
Signature: /s/ Barbara G. McClung, as attorney-in-fact
Stock symbol: CRBU
Transactions as of: Feb 20, 2025
Transactions value $: -$4,811
Form type: 4
Date filed: 2/21/2025, 08:19 PM
Previous filing: Feb 22, 2024
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CRBU	Common Stock	Award	$0	+37.5K	+113.64%	$0.00	70.5K	Feb 20, 2025	Direct	F1
transaction	CRBU	Common Stock	Sale	-$4.81K	-3.56K	-5.06%	$1.35	66.9K	Feb 21, 2025	Direct	F2, F3

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	Award	$0	+170K		$0.00	170K	Feb 20, 2025	Common Stock	170K	$1.41	Direct	F4

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

Explanation of Responses:

Id	Content
F1	This reflects restricted stock units ("RSUs") that vest in four equal annual installments beginning on February 20, 2026, subject to the reporting person's continued services to the Issuer through the applicable vesting dates. The RSUs will be settled in stock within 30 days after each vesting date.
F2	Reflects the number of shares of common stock that were sold in a "sell to cover" transaction for the sole purpose of satisfying tax withholding obligations in connection with the vesting of RSUs previously granted to the reporting person and does not represent a discretionary trade by the reporting person. This transaction was made pursuant to a Rule 10b5-1 trading plan in the form of a durable sell-to-cover instruction adopted prior to the 2023 amendments to Rule 10b5-1. The trading plan provides for the automatic sale of shares of common stock necessary to satisfy the reporting person's tax withholding obligations incurred in connection with the vesting of RSUs.
F3	This transaction was executed in multiple trades on 2/21/2025 at prices ranging from $1.32 to $1.35. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price within the specified range.
F4	25% of the options will vest upon the one-year anniversary of the grant date, February 20, 2026, and 1/48th will vest monthly thereafter over the 36-month period following the one-year cliff, subject to the reporting person's continued service to the Issuer through the applicable vesting dates.