Key facts
- This page summarizes Richard Roy Grisenthwaite's Form 4 filing for ARM HOLDINGS PLC /UK (ARM).
- 15 reported transactions and 6 derivative rows are listed below.
- Accepted by SEC: 19 May 2026, 17:20.
Richard Roy Grisenthwaite - 15 May 2026 Form 4 Insider Report for ARM HOLDINGS PLC /UK (ARM)
- Reporting relationship
- Chief Architect
- Issuer ticker
- ARM
- Reported as of
- 15 May 2026
- Net transaction value
- -$5,090,502
- SEC form
- 4
- Accepted by SEC
- 19 May 2026, 17:20:26 UTC
- Prior SEC filing
- 18 Mar 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ George Kanelos, as Attorney-in-Fact for Richard Roy Grisenthwaite
Source evidence
Original filing metadata and source links for verification.
4 source fields
Reporting owner
1 detail
Key filing fact
Richard Roy Grisenthwaite filed Form 4 for ARM HOLDINGS PLC /UK (ARM) on 19 May 2026.
Change
- Previous filing in this sequence was filed on 18 Mar 2026.
- Current net transaction value: -$5,090,502.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0002112445
Primary reporting owner
Grisenthwaite Richard Roy
- Relationship
- Chief Architect
- Address
- C/O ARM HOLDINGS PLC, 110 FULBOURN ROAD, CAMBRIDGE, UNITED KINGDOM
- Signature
- /s/ George Kanelos, as Attorney-in-Fact for Richard Roy Grisenthwaite
- Signature date
- 19 May 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
ARM
transaction
Ordinary Shares
Award
- Transaction value
- Shares
- +5,217
- Change %
- +1600%
- Price
- Shares after
- 5,543
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F2, F3
ARM
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +2,046
- Change %
- +37%
- Price
- Shares after
- 7,589
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F4
ARM
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +14,595
- Change %
- +192%
- Price
- Shares after
- 22,184
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F4
ARM
transaction
Ordinary Shares
Award
- Transaction value
- Shares
- +4,158
- Change %
- +19%
- Price
- Shares after
- 26,342
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F5
ARM
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +1,631
- Change %
- +6.2%
- Price
- Shares after
- 27,973
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F6
ARM
transaction
Ordinary Shares
Award
- Transaction value
- Shares
- +13,315
- Change %
- +48%
- Price
- Shares after
- 41,288
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F7
ARM
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +4,352
- Change %
- +11%
- Price
- Shares after
- 45,640
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F3, F8
ARM
transaction
Ordinary Shares
Tax liability
- Transaction value
- Shares
- -21,301
- Change %
- -47%
- Price
- $209.16*
- Shares after
- 24,339
- Date
- 15 May 2026
- Ownership
- Direct
- Footnotes
- F1, F9
ARM
transaction
Ordinary Shares
Sale
- Transaction value
- $5,090,502
- Shares
- -24,339
- Change %
- -100%
- Price
- $209.15
- Shares after
- 0
- Date
- 18 May 2026
- Ownership
- Direct
- Footnotes
- F1, F10
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
ARM
transaction
Derivative
Restricted Stock Units
Award
- Transaction value
- Shares
- +6,648
- Change %
- +6.7%
- Price
- $0.000000*
- Shares after
- 106,282
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 6,648
- Exercise price
- Footnotes
- F3, F11
ARM
transaction
Derivative
Restricted Stock Units
Award
- Transaction value
- Shares
- +34,785
- Change %
- +33%
- Price
- $0.000000*
- Shares after
- 141,067
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 34,785
- Exercise price
- Footnotes
- F3, F12
ARM
transaction
Derivative
Restricted Stock Units
Options Exercise
- Transaction value
- Shares
- -2,046
- Change %
- -1.5%
- Price
- $0.000000*
- Shares after
- 139,021
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 2,046
- Exercise price
- Footnotes
- F3, F4
ARM
transaction
Derivative
Restricted Stock Units
Options Exercise
- Transaction value
- Shares
- -14,595
- Change %
- -10%
- Price
- $0.000000*
- Shares after
- 124,426
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 14,595
- Exercise price
- Footnotes
- F3, F4
ARM
transaction
Derivative
Restricted Stock Units
Options Exercise
- Transaction value
- Shares
- -1,631
- Change %
- -1.3%
- Price
- $0.000000*
- Shares after
- 122,795
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 1,631
- Exercise price
- Footnotes
- F3, F6
ARM
transaction
Derivative
Restricted Stock Units
Options Exercise
- Transaction value
- Shares
- -4,352
- Change %
- -3.5%
- Price
- $0.000000*
- Shares after
- 118,443
- Date
- 15 May 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 4,352
- Exercise price
- Footnotes
- F3, F8
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 12 footnotes
Footnote 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.
Footnote F2
Represents performance-based restricted stock units granted on May 1, 2025, which vested on May 15, 2026, following certification of the satisfaction of certain performance conditions by the Remuneration Committee (the "Remuneration Committee") of the Board of Directors of the Company.
Footnote F3
Each restricted stock unit ("RSU") represents the right to receive, following vesting, 1 Ordinary Share held in the form of an ADS.
Footnote F4
This RSU award was granted on May 1, 2025. 30% of the award vested on May 15, 2026. 30% of the award will vest on May 15, 2027, and the remaining 40% will vest on May 15, 2028, subject to continued service to the Company.
Footnote F5
Represents performance-based RSUs granted on May 13, 2024, which vested on May 15, 2026, following certification of the satisfaction of certain performance conditions by the Remuneration Committee.
Footnote F6
This RSU award was granted on May 13, 2024, 30% of which vested on each of May 15, 2025 and May 15, 2026. The remaining 40% will vest on May 15, 2027, subject to continued service to the Company.
Footnote F7
Represents performance-based RSUs granted on May 23, 2023, which vested on May 15, 2026, following certification of the satisfaction of certain performance conditions by the Remuneration Committee.
Footnote F8
This RSU award was granted on May 23, 2023 and vested on May 15, 2026.
Footnote F9
Ordinary Shares withheld to satisfy tax withholding requirements on vesting of RSUs.
Footnote F10
Represents weighted average sales price. The shares were sold at prices ranging from $209.03 to $209.66. The reporting person will provide upon request, to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price
Footnote F11
This RSU award was granted effective May 15, 2026. 30% will vest on each of May 15, 2027, and May 15, 2028, and the remaining 40% will vest on May 15, 2029, subject to continued service to the Company.
Footnote F12
This RSU award was granted effective May 15, 2026. 50% will vest on each of May 15, 2028 and May 15, 2029, subject to continued service to the Company.