Arm Holdings Director Karen Dykstra Receives 1,531 Restricted Stock Units

This Form 4 filing reports that Karen E. Dykstra, a director of Arm Holdings PLC, received 1,531 restricted stock units (RSUs) on May 15, 2026. Each RSU represents the right to receive one ordinary share in the form of an American Depositary Share (ADS) following vesting. The RSUs will vest in full on May 15, 2027, subject to continued service, but the ADSs will not be delivered until the termination of Ms. Dykstra's service on the Board of Directors, as she elected to defer delivery. Following this transaction, Ms. Dykstra holds a total of 5,802 RSUs. The transaction was reported by attorney-in-fact George Kanelos on May 19, 2026.