MALLICK DHIRAJ (Chief Operating Officer) sold 396K shares of CEREBRAS SYSTEMS INC. on the open market

Open‑market sale worth $80.80M. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 19 sales

MALLICK DHIRAJ

Filed: 9/30/2026ACC: 0001628280-26-064042

InsiderMALLICK DHIRAJCIK 2039572

→

IssuerCEREBRAS SYSTEMS INC.CIK 2021728

Officer· Chief Operating Officer

Since May 2026

-396K

Net shares

Net seller

$80.80M

Total sold

Open market trades

0B · 19S

Total transactions

552K acquired · 948K disposed

Non-Derivative Transactions20

Class A Common Stock

Direct

C · Conversion

+276K

Price / share

—

Trade value

—

% of position

230.0%

9/29/2026

120K→396K

Class A Common Stock

Direct

S · Sale

−598.00

Price / share

$212.93

Trade value

$127.33K

% of position

0.2%

9/29/2026

396K→395.40K

Class A Common Stock

Direct

S · Sale

−18.27K

Price / share

$212.20

Trade value

$3.88M

% of position

4.6%

9/29/2026

395.40K→377.13K

Class A Common Stock

Direct

S · Sale

−41.39K

Price / share

$211.29

Trade value

$8.75M

% of position

11.0%

9/29/2026

377.13K→335.74K

Class A Common Stock

Direct

S · Sale

−46.43K

Price / share

$210.27

Trade value

$9.76M

% of position

13.8%

9/29/2026

335.74K→289.31K

Class A Common Stock

Direct

S · Sale

−41.28K

Price / share

$209.33

Trade value

$8.64M

% of position

14.3%

9/29/2026

289.31K→248.03K

Class A Common Stock

Direct

S · Sale

−20.71K

Price / share

$208.38

Trade value

$4.32M

% of position

8.4%

9/29/2026

248.03K→227.32K

Class A Common Stock

Direct

S · Sale

−9.65K

Price / share

$207.06

Trade value

$2M

% of position

4.2%

9/29/2026

227.32K→217.67K

Class A Common Stock

Direct

S · Sale

−9.05K

Price / share

$206.13

Trade value

$1.86M

% of position

4.2%

9/29/2026

217.67K→208.62K

Class A Common Stock

Direct

S · Sale

−8.73K

Price / share

$205.17

Trade value

$1.79M

% of position

4.2%

9/29/2026

208.62K→199.89K

Class A Common Stock

Direct

S · Sale

−27.49K

Price / share

$204.17

Trade value

$5.61M

% of position

13.8%

9/29/2026

199.89K→172.40K

Class A Common Stock

Direct

S · Sale

−9.68K

Price / share

$203.37

Trade value

$1.97M

% of position

5.6%

9/29/2026

172.40K→162.72K

Class A Common Stock

Direct

S · Sale

−5.64K

Price / share

$201.91

Trade value

$1.14M

% of position

3.5%

9/29/2026

162.72K→157.08K

Class A Common Stock

Direct

S · Sale

−22.91K

Price / share

$200.96

Trade value

$4.60M

% of position

14.6%

9/29/2026

157.08K→134.16K

Class A Common Stock

Direct

S · Sale

−17.85K

Price / share

$199.89

Trade value

$3.57M

% of position

13.3%

9/29/2026

134.16K→116.32K

Class A Common Stock

Direct

S · Sale

−17K

Price / share

$198.96

Trade value

$3.38M

% of position

14.6%

9/29/2026

116.32K→99.32K

Class A Common Stock

Direct

S · Sale

−5.17K

Price / share

$197.85

Trade value

$1.02M

% of position

5.2%

9/29/2026

99.32K→94.15K

Class A Common Stock

Direct

S · Sale

−6.61K

Price / share

$197.05

Trade value

$1.30M

% of position

7.0%

9/29/2026

94.15K→87.53K

Class A Common Stock

Direct

S · Sale

−18.70K

Price / share

$195.56

Trade value

$3.66M

% of position

21.4%

9/29/2026

87.53K→68.83K

Class A Common Stock

Direct

S · Sale

−68.83K

Price / share

$194.91

Trade value

$13.42M

% of position

New position

9/29/2026

68.83K→0.00

Total

Net shares

−120K

Net value

-$80.80M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Class A Common Stock Direct	9/29/2026	C · Conversion	+276K	—	—	230.0%	120K	396K
Class A Common Stock Direct	9/29/2026	S · Sale	−598.00	$212.93	$127.33K	0.2%	396K	395.40K
Class A Common Stock Direct	9/29/2026	S · Sale	−18.27K	$212.20	$3.88M	4.6%	395.40K	377.13K
Class A Common Stock Direct	9/29/2026	S · Sale	−41.39K	$211.29	$8.75M	11.0%	377.13K	335.74K
Class A Common Stock Direct	9/29/2026	S · Sale	−46.43K	$210.27	$9.76M	13.8%	335.74K	289.31K
Class A Common Stock Direct	9/29/2026	S · Sale	−41.28K	$209.33	$8.64M	14.3%	289.31K	248.03K
Class A Common Stock Direct	9/29/2026	S · Sale	−20.71K	$208.38	$4.32M	8.4%	248.03K	227.32K
Class A Common Stock Direct	9/29/2026	S · Sale	−9.65K	$207.06	$2M	4.2%	227.32K	217.67K
Class A Common Stock Direct	9/29/2026	S · Sale	−9.05K	$206.13	$1.86M	4.2%	217.67K	208.62K
Class A Common Stock Direct	9/29/2026	S · Sale	−8.73K	$205.17	$1.79M	4.2%	208.62K	199.89K
Class A Common Stock Direct	9/29/2026	S · Sale	−27.49K	$204.17	$5.61M	13.8%	199.89K	172.40K
Class A Common Stock Direct	9/29/2026	S · Sale	−9.68K	$203.37	$1.97M	5.6%	172.40K	162.72K
Class A Common Stock Direct	9/29/2026	S · Sale	−5.64K	$201.91	$1.14M	3.5%	162.72K	157.08K
Class A Common Stock Direct	9/29/2026	S · Sale	−22.91K	$200.96	$4.60M	14.6%	157.08K	134.16K
Class A Common Stock Direct	9/29/2026	S · Sale	−17.85K	$199.89	$3.57M	13.3%	134.16K	116.32K
Class A Common Stock Direct	9/29/2026	S · Sale	−17K	$198.96	$3.38M	14.6%	116.32K	99.32K
Class A Common Stock Direct	9/29/2026	S · Sale	−5.17K	$197.85	$1.02M	5.2%	99.32K	94.15K
Class A Common Stock Direct	9/29/2026	S · Sale	−6.61K	$197.05	$1.30M	7.0%	94.15K	87.53K
Class A Common Stock Direct	9/29/2026	S · Sale	−18.70K	$195.56	$3.66M	21.4%	87.53K	68.83K
Class A Common Stock Direct	9/29/2026	S · Sale	−68.83K	$194.91	$13.42M	New position	68.83K	0.00
Total			−120K		-$80.80M

Derivative Transactions3

Stock Option

Direct

M · Option Exercise

Converts to

Class B Common Stock

276K shares

−276K

Strike price

0.98

Held after

91.37K

Exercisable

—

9/29/2026

Class B Common Stock

Direct

M · Option Exercise

Converts to

Class A Common Stock

276K shares

+276K

Strike price

Held after

796.81K

Exercisable

—

9/29/2026

Class B Common Stock

Direct

C · Conversion

Converts to

Class A Common Stock

276K shares

−276K

Strike price

Held after

520.81K

Exercisable

—

9/29/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Stock Option Direct	Class B Common Stock276K shares	9/29/2026	M · Option Exercise	−276K	0.98	—	91.37K
Class B Common Stock Direct	Class A Common Stock276K shares	9/29/2026	M · Option Exercise	+276K		—	796.81K
Class B Common Stock Direct	Class A Common Stock276K shares	9/29/2026	C · Conversion	−276K		—	520.81K