Grisenthwaite Richard Roy 4

What Happened

• Richard Roy Grisenthwaite, Chief Architect at ARM Holdings plc, had multiple RSU/derivative transactions reported May 15, 2026 and subsequently disposed of shares. Following vesting/conversion/exercise activity, 21,301 ADSs were surrendered to satisfy tax withholding on May 15 (valued at $4,455,317 at $209.16), and an additional 24,339 ADSs were sold in an open-market transaction on May 18, 2026 for $5,090,502 (weighted average price $209.15; sales ranged $209.03–$209.66).

Key Details

• Primary dates: May 15, 2026 (awards, vesting/conversion/exercises; tax withholding), May 18, 2026 (open-market sale). Filing date: May 19, 2026 (reports May 15 transactions).
• Dispositions: 21,301 ADSs withheld for taxes at $209.16 = $4,455,317 (code F); 24,339 ADSs sold publicly at a weighted avg $209.15 = $5,090,502 (code S). Weighted sale price range: $209.03–$209.66.
• Conversion/exercise activity: multiple exercise/conversion entries (code M) on May 15 converting derivative awards to shares/ADSs.
• Award activity: several RSU grants/awards reported (code A) on May 15, including awards with future vesting schedules (see footnotes F11, F12).
• Footnotes: ADSs represent ordinary shares (F1); some RSUs were performance-based and vested following certification (F2, F5, F7); F9 notes ordinary shares were withheld to satisfy tax obligations on RSU vesting; F10 provides sale price breakdown on request.
• Shares owned after the transactions were not specified in the filing.

Context

• The filings show typical post-vesting activity: RSUs/performance awards converted to ADSs (M/A codes), shares were withheld to cover tax obligations (F), and remaining shares were sold in the open market (S). This pattern is generally a cashless exercise/settlement plus routine sale rather than a straightforward purchase. No 10% owner or gift (G) activity is indicated.