Arm

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-09-21 10b5-1 Pre-arranged Plan: Yes --- Issuer --- Name: ARM HOLDINGS PLC /UK (ARM) CIK: 0001973239 --- Reporting Owner --- Name: Child Jason CIK: 0001533913 Role: Officer (Chief Financial Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Ordinary Shares Date: 2026-09-21 | Code: S (Open market sale) Shares: -10,400 | Price: $300.00 Total Value: $3,120,000.00 Shares Owned After: 153,442 | Ownership: D (Direct) Footnotes: [F1] Ordinary shares, nominal value 0.001 GBP per share ("Ordinary Shares"), are held in the form of American Depositary Shares ("ADSs"). Each ADS represents 1 Ordinary Share. [F2] The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 22, 2026. [F3] Includes 10 ordinary shares acquired under the Arm Holdings plc 2024 Employee Stock Purchase Plan on August 31, 2026. --- Footnotes (Complete Index) --- F1: Ordinary shares, nominal value 0.001 GBP per share ("Ordinary Shares"), are held in the form of American Depositary Shares ("ADSs"). Each ADS represents 1 Ordinary Share. F2: The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 22, 2026. F3: Includes 10 ordinary shares acquired under the Arm Holdings plc 2024 Employee Stock Purchase Plan on August 31, 2026. --- Signature --- /s/ /s/ George Kanelos, as Attorney-in-Fact for Jason Child (2026-09-23)