LIE SEAN (Chief Technology Officer) sold 13.4% of their position (53.46K shares) of CEREBRAS SYSTEMS INC. on the open market

Open‑market sale worth $11.24M — a moderate reduction. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 1 sale

LIE SEAN

Filed: 9/9/2026ACC: 0001628280-26-060988

InsiderLIE SEANCIK 2132472

→

IssuerCEREBRAS SYSTEMS INC.CIK 2021728

Officer10% Owner· Chief Technology Officer

Since May 2026

-69.50K

Net shares

Net seller

$11.24M

Total sold

Open market trades

0B · 1S

Total transactions

92.28K acquired · 161.78K disposed

Non-Derivative Transactions3

Class A Common Stock

Direct

C · Conversion

+46.14K

Price / share

—

Trade value

—

% of position

12.5%

9/4/2026

368.93K→415.07K

Class A Common Stock

Direct

G · Gift

−16.04K

Price / share

—

Trade value

—

% of position

3.9%

9/4/2026

415.07K→399.03K

Class A Common Stock

Direct

S · Sale

−53.46K

Price / share

$210.16

Trade value

$11.24M

% of position

13.4%

9/4/2026

399.03K→345.57K

Total

Net shares

−23.36K

Net value

-$11.24M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Class A Common Stock Direct	9/4/2026	C · Conversion	+46.14K	—	—	12.5%	368.93K	415.07K
Class A Common Stock Direct	9/4/2026	G · Gift	−16.04K	—	—	3.9%	415.07K	399.03K
Class A Common Stock Direct	9/4/2026	S · Sale	−53.46K	$210.16	$11.24M	13.4%	399.03K	345.57K
Total			−23.36K		-$11.24M

Derivative Transactions3

Stock Option

Direct

M · Option Exercise

Converts to

Class B Common Stock

46.14K shares

−46.14K

Strike price

5.48

Held after

289.02K

Exercisable

—

9/4/2026

Class B Common Stock

Direct

M · Option Exercise

Converts to

Class A Common Stock

46.14K shares

+46.14K

Strike price

Held after

7.63M

Exercisable

—

9/4/2026

Class B Common Stock

Direct

C · Conversion

Converts to

Class A Common Stock

46.14K shares

−46.14K

Strike price

Held after

7.58M

Exercisable

—

9/4/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Stock Option Direct	Class B Common Stock46.14K shares	9/4/2026	M · Option Exercise	−46.14K	5.48	—	289.02K
Class B Common Stock Direct	Class A Common Stock46.14K shares	9/4/2026	M · Option Exercise	+46.14K		—	7.63M
Class B Common Stock Direct	Class A Common Stock46.14K shares	9/4/2026	C · Conversion	−46.14K		—	7.58M

Non-Derivative Holdings (Post-Transaction)0

No non-derivative holdings reported

Derivative Holdings (Post-Transaction)1

Class B Common Stock

Indirect

Underlying security

Class A Common Stock

Underlying shares

180.60K

Shares owned

180.60K

Exercise price

Expiration

—

Exercise window

—

Total

Underlying

180.60K

Owned

180.60K

Security	Underlying	Exercise Price	Exercise Window	Expiration	Underlying Shares	Shares Owned
Class B Common Stock Indirect	Class A Common Stock		—	—	180.60K	180.60K
Total					180.60K	180.60K