Richard Roy Grisenthwaite is Chief Architect at ARM HOLDINGS PLC /UK (ARM). They have made 1 open-market trade across 1 company since 2026, most recently 2026-05-18.
CIK 0002112445
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 1 sale. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| ARM | 24,339 | $5.5M |
Shares reported on the most recent Form 4, priced at the 2026-05-19 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| ARM | SELL | 2026-05-18 | 2026-05-19 | $209.15 | $5.1M | +79.9% | +93.3% | +19.5% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.