Caribou Biosciences (CRBU) CTO sells 6,228 shares in open-market trade

Rhea-AI Filing Summary

Caribou Biosciences, Inc. Chief Technology Officer Timothy P. Kelly reported an open-market sale of 6,228 shares of common stock at $1.93 per share. After this February 25, 2026 transaction, he directly owns 73,125 shares of Caribou Biosciences common stock.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Kelly Timothy P

(Last) (First) (Middle)

C/O CARIBOU BIOSCIENCES, INC.

2929 7TH STREET, SUITE 105

(Street)

BERKELEY CA 94710

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Caribou Biosciences, Inc. [ CRBU ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Technology Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/25/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/25/2026		S		6,228	D	$1.93	73,125	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

	/s/ Barbara G. McClung, as attorney-in-fact	02/27/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Caribou Biosciences (CRBU) report for Timothy P. Kelly?

Caribou Biosciences reported that Chief Technology Officer Timothy P. Kelly sold 6,228 shares of common stock. The sale was an open-market transaction at $1.93 per share on February 25, 2026, as disclosed in a Form 4 filing.

At what price did Timothy P. Kelly sell Caribou Biosciences (CRBU) shares?

Timothy P. Kelly sold Caribou Biosciences common stock at an average price of $1.93 per share. The Form 4 notes this as an open-market sale, reflecting the per-share price for the 6,228 shares transacted on February 25, 2026.

How many Caribou Biosciences (CRBU) shares does Timothy P. Kelly hold after the sale?

After the reported sale, Timothy P. Kelly directly holds 73,125 shares of Caribou Biosciences common stock. This post-transaction ownership figure is disclosed in the Form 4 and reflects his remaining direct position following the 6,228-share open-market sale.

What role does Timothy P. Kelly hold at Caribou Biosciences (CRBU)?

Timothy P. Kelly serves as Chief Technology Officer at Caribou Biosciences. His position is identified in the Form 4 filing, which reports his insider status and the details of his open-market sale of 6,228 shares of common stock at $1.93 per share.

Was the Caribou Biosciences (CRBU) insider transaction a buy or a sell?

The transaction was a sale of common stock. The Form 4 classifies it with code “S,” indicating a sale in an open market or private transaction, and shows 6,228 shares sold at $1.93 per share by Timothy P. Kelly.

Is Timothy P. Kelly’s Caribou Biosciences (CRBU) ownership direct or indirect?

Timothy P. Kelly’s reported holdings are classified as direct ownership. The Form 4 lists the ownership code as “D,” indicating that the 73,125 shares he holds following the 6,228-share sale are owned directly, with no separate entity attribution disclosed.