GRISENTHWAITE RICHARD ROY (Chief Architect) sold 24.34K shares of ARM HOLDINGS PLC /UK on the open market

Open‑market sale worth $5.09M. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 1 sale

GRISENTHWAITE RICHARD ROY

Filed: 5/19/2026ACC: 0001973239-26-000076

InsiderGRISENTHWAITE RICHARD ROYCIK 2112445

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IssuerARM HOLDINGS PLC /UKCIK 1973239

Officer· Chief Architect

Since Mar 2026

+18.48K

Net shares

Net buyer

$9.55M

Total sold

Open market trades

0B · 1S

Total transactions

86.75K acquired · 68.26K disposed

Non-Derivative Transactions9

Ordinary Shares

Direct

A · Award

+5.22K

Price / share

—

Trade value

—

% of position

1600.3%

5/15/2026

326.00→5.54K

Ordinary Shares

Direct

M · Option Exercise

+2.05K

Price / share

—

Trade value

—

% of position

36.9%

5/15/2026

5.54K→7.59K

Ordinary Shares

Direct

M · Option Exercise

+14.60K

Price / share

—

Trade value

—

% of position

192.3%

5/15/2026

7.59K→22.18K

Ordinary Shares

Direct

A · Award

+4.16K

Price / share

—

Trade value

—

% of position

18.7%

5/15/2026

22.18K→26.34K

Ordinary Shares

Direct

M · Option Exercise

+1.63K

Price / share

—

Trade value

—

% of position

6.2%

5/15/2026

26.34K→27.97K

Ordinary Shares

Direct

A · Award

+13.31K

Price / share

—

Trade value

—

% of position

47.6%

5/15/2026

27.97K→41.29K

Ordinary Shares

Direct

M · Option Exercise

+4.35K

Price / share

—

Trade value

—

% of position

10.5%

5/15/2026

41.29K→45.64K

Ordinary Shares

Direct

F · Tax Withholding

−21.30K

Price / share

$209.16

Trade value

$4.46M

% of position

46.7%

5/15/2026

45.64K→24.34K

Ordinary Shares

Direct

S · Sale

−24.34K

Price / share

$209.15

Trade value

$5.09M

% of position

New position

5/18/2026

24.34K→0.00

Total

Net shares

−326.00

Net value

-$9.55M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Ordinary Shares Direct	5/15/2026	A · Award	+5.22K	—	—	1600.3%	326.00	5.54K
Ordinary Shares Direct	5/15/2026	M · Option Exercise	+2.05K	—	—	36.9%	5.54K	7.59K
Ordinary Shares Direct	5/15/2026	M · Option Exercise	+14.60K	—	—	192.3%	7.59K	22.18K
Ordinary Shares Direct	5/15/2026	A · Award	+4.16K	—	—	18.7%	22.18K	26.34K
Ordinary Shares Direct	5/15/2026	M · Option Exercise	+1.63K	—	—	6.2%	26.34K	27.97K
Ordinary Shares Direct	5/15/2026	A · Award	+13.31K	—	—	47.6%	27.97K	41.29K
Ordinary Shares Direct	5/15/2026	M · Option Exercise	+4.35K	—	—	10.5%	41.29K	45.64K
Ordinary Shares Direct	5/15/2026	F · Tax Withholding	−21.30K	$209.16	$4.46M	46.7%	45.64K	24.34K
Ordinary Shares Direct	5/18/2026	S · Sale	−24.34K	$209.15	$5.09M	New position	24.34K	0.00
Total			−326.00		-$9.55M

Derivative Transactions6

Restricted Stock Units

Direct

A · Award

Converts to

Ordinary Shares

6.65K shares

+6.65K

Strike price

Held after

106.28K

Exercisable

—

5/15/2026

Restricted Stock Units

Direct

A · Award

Converts to

Ordinary Shares

34.78K shares

+34.78K

Strike price

Held after

141.07K

Exercisable

—

5/15/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Ordinary Shares

2.05K shares

−2.05K

Strike price

Held after

139.02K

Exercisable

—

5/15/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Ordinary Shares

14.60K shares

−14.60K

Strike price

Held after

124.43K

Exercisable

—

5/15/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Ordinary Shares

1.63K shares

−1.63K

Strike price

Held after

122.80K

Exercisable

—

5/15/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Ordinary Shares

4.35K shares

−4.35K

Strike price

Held after

118.44K

Exercisable

—

5/15/2026

Security	Converts To	Date	Type	Shares	Exercisable	Held After
Restricted Stock Units Direct	Ordinary Shares6.65K shares	5/15/2026	A · Award	+6.65K	—	106.28K
Restricted Stock Units Direct	Ordinary Shares34.78K shares	5/15/2026	A · Award	+34.78K	—	141.07K
Restricted Stock Units Direct	Ordinary Shares2.05K shares	5/15/2026	M · Option Exercise	−2.05K	—	139.02K
Restricted Stock Units Direct	Ordinary Shares14.60K shares	5/15/2026	M · Option Exercise	−14.60K	—	124.43K
Restricted Stock Units Direct	Ordinary Shares1.63K shares	5/15/2026	M · Option Exercise	−1.63K	—	122.80K
Restricted Stock Units Direct	Ordinary Shares4.35K shares	5/15/2026	M · Option Exercise	−4.35K	—	118.44K