Director Rosemary Schooler discloses ARM (ARM) share and RSU holdings

Rhea-AI Filing Summary

ARM Holdings plc director Rosemary Schooler filed an initial ownership report showing her current equity position. She directly holds 7,431 Ordinary Shares in the form of American Depositary Shares, and 2,141 restricted stock units that each represent one Ordinary Share.

The restricted stock units are scheduled to vest in full on May 15, 2026, subject to her continued service to ARM Holdings plc. After vesting, each unit will deliver one Ordinary Share held as an ADS.

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^*

Schooler Rosemary

(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)

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

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)	7,431	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)	2,141	(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. The restricted stock units ("RSUs") will vest in full on May 15, 2026, subject to continued service to Arm Holdings plc.

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

Remarks:

Exhibit 24 - Power of Attorney

	/s/ George Kanelos, as Attorney-in-Fact for Rosemary Schooler	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 Rosemary Schooler’s Form 3 filing show for ARM (ARM)?

The Form 3 shows Rosemary Schooler’s initial ownership in ARM, including 7,431 Ordinary Shares and 2,141 restricted stock units. It establishes her baseline equity position as a director rather than reporting any new purchase or sale transactions.

How many ARM (ARM) shares does Rosemary Schooler directly own?

Rosemary Schooler directly holds 7,431 Ordinary Shares of ARM in the form of American Depositary Shares. This figure reflects her direct equity stake reported in the Form 3 and serves as a starting point for tracking any future changes in her holdings.

What restricted stock units does Rosemary Schooler hold in ARM (ARM)?

She holds 2,141 restricted stock units, each representing the right to receive one Ordinary Share. These units are part of her equity compensation and give her future share delivery, subject to vesting conditions tied to continued service at ARM Holdings plc.

When do Rosemary Schooler’s ARM (ARM) restricted stock units vest?

Her restricted stock units are scheduled to vest in full on May 15, 2026, subject to continued service. Once vested, each unit converts into one Ordinary Share, which is held in the form of an American Depositary Share, aligning her compensation with shareholder value.

How are ARM (ARM) Ordinary Shares represented in this Form 3 filing?

The filing explains that ARM Ordinary Shares are held in the form of American Depositary Shares. Each ADS represents one Ordinary Share, so the 7,431 Ordinary Shares and any shares from vested restricted stock units are reflected through equivalent ADS positions.