Arm Holdings (ARM) CCO William Abbey details RSU and share holdings

Rhea-AI Filing Summary

Arm Holdings plc Chief Commercial Officer William Abbey has filed an initial ownership report showing his equity interests in the company. As of March 18, 2026, he holds 48,201 Ordinary Shares directly, along with several restricted stock unit (RSU) awards that can convert into Ordinary Shares.

The RSUs are tied to service-based vesting schedules. One award granted on December 9, 2025 covers 36,005 underlying Ordinary Shares, vesting 30% on each of November 15, 2026 and November 15, 2027, and 40% on November 15, 2028. Another award granted on May 1, 2025 covers 5,838 underlying Ordinary Shares, vesting 30% on each of May 15, 2026 and May 15, 2027, and 40% on May 15, 2028.

Additional RSU grants include a May 13, 2024 award originally for 5,809 units, of which 30% has already vested, with 30% vesting on May 15, 2026 and 40% on May 15, 2027, and a May 23, 2023 award that will vest on May 15, 2026. Each RSU represents the right to receive one Ordinary Share held in the form of an American Depositary Share.

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

Abbey William

(Last) (First) (Middle)

C/O ARM HOLDINGS PLC

110 FULBOURN ROAD

(Street)

CAMBRIDGE CB1 9NJ

(City) (State) (Zip)

UNITED STATES

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
03/18/2026

3. Issuer Name and Ticker or Trading Symbol
ARM HOLDINGS PLC /UK [ ARM ]

3a. Foreign Trading Symbol

5. If Amendment, Date of Original Filed (Month/Day/Year)

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Commercial Officer

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Ordinary Shares(1)	48,201	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(2)	(2)	Ordinary Shares(1)	36,005	(3)	D
Restricted Stock Units	(4)	(4)	Ordinary Shares(1)	5,838	(3)	D
Restricted Stock Units	(5)	(5)	Ordinary Shares(1)	4,067	(3)	D
Restricted Stock Units	(6)	(6)	Ordinary Shares(1)	4,706	(3)	D

Explanation of Responses:

1. 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.

2. This restricted stock unit ("RSU") award was granted on December 9, 2025. 30% will vest on each of November 15, 2026, and November 15, 2027, and the remaining 40% will vest on November 15, 2028, subject to continued service to Arm Holdings plc (the "Company").

3. Each RSU represents the right to receive, following vesting, 1 Ordinary Share held in the form of an ADS.

4. This RSU award was granted on May 1, 2025. 30% will vest on each of May 15, 2026 and May 15, 2027, and the remaining 40% will vest on May 15, 2028, subject to continued service to the Company.

5. This RSU award of 5,809 was granted on May 13, 2024, of which 30% already vested on May 15, 2025. 30% will vest on May 15, 2026 and 40% will vest on May 15, 2027, subject to continued service to the Company.

6. This RSU award was granted on May 23, 2023 and will vest on May 15, 2026, subject to continued service to the Company.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ George Kanelos, as Attorney-in-Fact for William Abbey	03/18/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 3: SEC 1473 (03-26)

FAQ

What does Arm (ARM) Chief Commercial Officer William Abbey report on this Form 3?

William Abbey reports his initial ownership in Arm Holdings plc. He discloses 48,201 Ordinary Shares held directly plus several restricted stock unit awards that can convert into additional Ordinary Shares over time, all subject to specific service-based vesting schedules.

How many Arm (ARM) Ordinary Shares does William Abbey directly hold?

William Abbey directly holds 48,201 Ordinary Shares. These are separate from his restricted stock units, which represent additional potential Ordinary Shares that may be delivered in the future if the vesting conditions tied to continued service are satisfied.

What are the key terms of William Abbey’s December 9, 2025 RSU grant at Arm (ARM)?

The December 9, 2025 RSU grant covers 36,005 underlying Ordinary Shares. Thirty percent vests on November 15, 2026, another 30% on November 15, 2027, and the remaining 40% on November 15, 2028, assuming continued service to Arm Holdings plc.

How do William Abbey’s RSUs in Arm (ARM) convert into Ordinary Shares?

Each restricted stock unit represents one Ordinary Share held as an ADS. After vesting, each RSU entitles Abbey to receive one Ordinary Share in American Depositary Share form, aligning his compensation with the company’s equity over multiple future vesting dates.

What vesting schedule applies to William Abbey’s May 1, 2025 RSU award at Arm (ARM)?

The May 1, 2025 RSU award covers 5,838 underlying Ordinary Shares. Thirty percent vests on May 15, 2026, another 30% on May 15, 2027, and the final 40% on May 15, 2028, contingent on his continued service to the company.

What does the earlier May 13, 2024 RSU grant disclose about William Abbey’s Arm (ARM) equity?

The May 13, 2024 RSU grant was originally for 5,809 units. Thirty percent vested on May 15, 2025, with another 30% vesting on May 15, 2026 and the remaining 40% on May 15, 2027, provided he continues serving the company.