Rachel E. Haurwitz - 20 Feb 2026 Form 4 Insider Report for Caribou Biosciences, Inc. (CRBU)

Reporting relationship: President and CEO, Director
Issuer ticker: CRBU
Reported as of: 20 Feb 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 20 Feb 2026, 17:26:26 UTC
Prior SEC filing: 17 Mar 2025
Source filing: View source filing
Reporting owner signature: /s/ Barbara G. McClung, as attorney-in-fact

Key filing fact

Rachel E. Haurwitz filed Form 4 for Caribou Biosciences, Inc. (CRBU) on 20 Feb 2026.

Key facts

This page summarizes Rachel E. Haurwitz's Form 4 filing for Caribou Biosciences, Inc. (CRBU).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 20 Feb 2026, 17:26.

Change

Previous filing in this sequence was filed on 17 Mar 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001670579 Primary reporting owner

Haurwitz Rachel E.

Relationship: President and CEO, Director
Address: C/O CARIBOU BIOSCIENCES, INC., 2929 7TH STREET, SUITE 105, BERKELEY
Signature: /s/ Barbara G. McClung, as attorney-in-fact
Signature date: 20 Feb 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CRBU transaction

Common Stock

Award

Transaction value: $0
Shares: +151,700
Change %: +51%
Price: $0.000000
Shares after: 447,150
Date: 20 Feb 2026
Ownership: Direct
Footnotes: F1

CRBU holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 3,369,395
Date: 20 Feb 2026
Ownership: By Trust
Footnotes: F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CRBU transaction Derivative

Option to purchase Common Stock

Award

Transaction value: $0
Shares: +682,500
Change %
Price: $0.000000
Shares after: 682,500
Date: 20 Feb 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 682,500
Exercise price: $1.80
Footnotes: F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

This reflects restricted stock units ("RSUs") that vest in four equal annual installments beginning on February 20, 2027, subject to the reporting person continuing to provide service to the Issuer through the applicable vesting dates. The RSUs will be settled in stock within 30 days after each vesting date.

Footnote F2

Shares are held by The City Canyon Family Trust dated May 31, 2021, of which the Reporting Person is a Co-Trustee with her spouse.

Footnote F3

1/48 of the total number of shares subject to this option will vest on each monthly anniversary of the grant date such that the option will be fully vested on February 20, 2030, subject to the reporting person continuing to provide service to the Issuer through each such vesting date.

SEC remarks

The reporting person has elected, consistent with the terms of a durable sell-to-cover instruction, to pay cash to satisfy withholding tax obligations due in connection with the February 20, 2026 vesting of previously-granted RSUs.