Kelly Timothy P 4
4 · Caribou Biosciences, Inc. · Filed Feb 24, 2026
Insider Transaction Report
Form 4
Kelly Timothy P
Chief Technology Officer
Transactions
- Award
Common Stock
[F1]2026-02-20+45,000→ 82,500 total - Sale
Common Stock
[F2]2026-02-24$1.96/sh−3,147$6,168→ 79,353 total - Award
Option to purchase Common Stock
[F3]2026-02-20+202,500→ 202,500 totalExercise: $1.80Exp: 2036-02-19→ Common Stock (202,500 underlying)
Footnotes (3)
- [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.
- [F2]Reflects the number of shares of common stock that were sold pursuant to the Issuer's mandatory sell-to-cover policy 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.
- [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.
Signature
/s/ Barbara G. McClung, as attorney-in-fact|2026-02-24