CBRSCerebras Systems Inc. · Insider ownership research

Cerebras Systems Inc. insiders sold $408M in the past 12 months. How much of their stake is that?

Insiders sold $408M in the past 12 months.85% was sold under disclosed trading plans, 6% to cover taxes, 9% with no plan disclosed. The largest seller, Sean Lie (Chief Technology Officer), sold $194M. 72% of these sales were shares from exercising options.Share-of-stake figures for this company are being verified and will be added when that check is finished. Why

Updated Oct 13, 2026 from SEC filings · covers Oct 14, 2025 to Oct 13, 2026

$36.3M

sold with no plan disclosed, past 12 months

85%

of sales were under disclosed trading plans, past 12 months

7 of 10

officers and directors sold shares, past 12 months

Latest filing: Filed Oct 7 for a transaction on Oct 5. Eric Vishria reported a change in holdings. Filing

SEC ownership filings: 74 filed in the 12 months to Oct 13, 2026; 74 on record since May 13, 2026 · See the evidence

What stands out

Three insiders sold $36.3M with no disclosed plan: Steven Vassallo ($21.4M), Dhiraj Mallick ($13.4M) and Yagnesh Patel ($1.4M). The filings don't state a reason.Steven Vassallo: largest such sale, Sep 4, 2026 · Dhiraj Mallick: largest such sale, Jun 30, 2026 · Yagnesh Patel: largest such sale, Jun 25, 2026

Selling picked up in the last 90 days: officers and directors sold 1.86M shares, against an average of 38K per 90 days earlier in the period. Most of it was Sean Lie (921K shares in the last 90 days) and Dhiraj Mallick (435K shares in the last 90 days); 89% of these sales were under disclosed plans.Sean Lie: largest recent sale, Aug 20, 2026 · Dhiraj Mallick: largest recent sale, Sep 29, 2026

A share of stake is shown for 0 of the 7 officers and directors who sold. 10 are left out

i

Left out: Andrew Feldman, Lior Susan, Sean Lie, Robert Komin Jr., Paul Auvil III, Yagnesh Patel, Dhiraj Mallick, Elena Donio, Eric Vishria and Steven Vassallo (share of stake is being verified).

Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Their share of stake is being verified and is not shown yet; amounts and trading plans are below.

Sean Lie

Chief Technology Officer

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$194M97% planned, 3% to cover taxes

Dhiraj Mallick

Chief Operating Officer

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$104M78% planned, 9% to cover taxes 13% no plan disclosed

Andrew Feldman

CEO, President, Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$64.3M86% planned, 14% to cover taxes

Steven Vassallo

Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$21.4MNo plan disclosed

Eric Vishria

Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$15.7MDisclosed plan

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

Disclosed planTo cover taxesNo plan disclosedOne dollar scale for every month; the tallest bar is labeled

Recent activity

Past 30 days, Sep 14, 2026 to Oct 13, 2026

Sep 29, 20262 executives sold 429K shares ($87.4M) under a disclosed trading plan. 276K shares came in from vesting or option exercises the same day, so their combined holdings fell by 153K net.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Dhiraj Mallick Chief Operating Officer	396,000	$204.04	n/a	n/a	Sep 29, 2026	Sep 30, 2026
Robert Komin Jr. Chief Financial Officer	32,500	$203.53	n/a	n/a	Sep 29, 2026	Sep 30, 2026

Sep 28, 2026Yagnesh Patel sold 1.3K shares ($270K) under a disclosed trading plan.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Yagnesh Patel Chief Accounting Officer	1,320	$204.50	n/a	n/a	Sep 28, 2026	Sep 30, 2026

Sep 25, 2026Sean Lie sold 120K shares ($25.1M) under a disclosed trading plan. 120K shares came in from vesting or option exercises the same day, so the holding fell by 36K net.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Sean Lie Chief Technology Officer	120,000	$208.97	n/a	n/a	Sep 25, 2026	Sep 28, 2026

Sep 25, 2026Sean Lie gave away 36K shares as a gift. 120K shares came in from vesting or option exercises the same day, so the holding fell by 36K net.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Sean Lie Chief Technology Officer	36,000	n/a	n/a	n/a	Sep 25, 2026	Sep 28, 2026

Share-class conversions: 2 conversions, 396,000 shares Class B → Class A. A conversion is not a sale; the combined stake does not change.

"% of total stake" is the shares in an event against all the vested shares the person held that day, across every share class and holding entity, after that day's vesting. "n/a" means the person's holdings are not confirmed, or the row is a purchase. "Holdings record incomplete" means more shares were sold than the filings show the person held that day, so a percentage would be wrong.

Outside holders, reported separately

Benchmark Capital Management Co. VIII, L.L.C., Benchmark AI Infrastructure Management Co., L.L.C. and Foundation Capital Management Co. VIII, L.L.C. and 1 more reported no open-market sales in the past 12 months. Large shareholders and the funds or companies that board members represent are not part of management, so they are left out of the figures above.

Common questions

Is the Cerebras Systems Inc. CEO selling stock?

Yes. Andrew Feldman sold 320K shares ($64.3M) in the past 12 months, 86% of it under a trading plan disclosed in the filings.

Why are Cerebras Systems Inc. insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 85% of sales by value ran under 10b5-1 trading plans disclosed in the filings, 6% were to cover taxes and 9% had no disclosed plan. A trading plan schedules sales in advance.

Are any Cerebras Systems Inc. insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

The evidence

Who sold7 officers and directors: amount, % of holdings, trading plan

Who sold	Amount	% of holdings	Trading plan
Sean Lie Chief Technology Officer	$194M 931K shares	Not confirmed share of stake is being verified. Why	97% under a disclosed plan, 3% to cover taxes
Dhiraj Mallick Chief Operating Officer	$104M 514K shares	Not confirmed share of stake is being verified. Why	78% under a disclosed plan, 9% to cover taxes 13% no plan disclosed
Andrew Feldman CEO, President, Director	$64.3M 320K shares	Not confirmed share of stake is being verified. Why	86% under a disclosed plan, 14% to cover taxes
Steven Vassallo Director	$21.4M 100K shares	Not confirmed share of stake is being verified. Why	No plan disclosed
Eric Vishria Director	$15.7M 68K shares	Not confirmed share of stake is being verified. Why	Disclosed plan
Robert Komin Jr. Chief Financial Officer	$6.6M 33K shares	Not confirmed share of stake is being verified. Why	Disclosed plan
Yagnesh Patel Chief Accounting Officer	$3.0M 16K shares	Not confirmed share of stake is being verified. Why	9% under a disclosed plan, 43% to cover taxes 48% no plan disclosed

Sold by a charitable foundation the insider reports: Foundation Capital Leadership Fund II, L.P, Foundation Capital Management Co. LF II, L.L.C, Foundation Capital Management Co. VIII, L.L.C, Foundation Capital VIII Principals Fund, L.L.C, Foundation Capital VIII Principals Fund, LLC, Foundation Capital VIII and Foundation Capital Principals, Foundation Capital VIII, L.P, reported by Steven Vassallo. A foundation's shares are not the insider's own stake, so they are left out of the figures above.

Outside holder, reported separately: Benchmark Capital Management Co. VIII, L.L.C. (a 10% owner, not part of management). No open-market sales reported in the period. Latest filing

Outside holder, reported separately: Benchmark AI Infrastructure Management Co., L.L.C. (a 10% owner, not part of management). No open-market sales reported in the period. Latest filing

Outside holder, reported separately: Foundation Capital Management Co. VIII, L.L.C. (a 10% owner, not part of management). No open-market sales reported in the period. Latest filing

The full ownership picture0 of 10 officers and directors confirmed

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

Insider

Held Oct 13, 2025

Sold

Held Oct 13, 2026

Still held

Andrew Feldman

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Andrew Feldman are complete.

CEO, President, Director

n/a

−320K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Andrew Feldman

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Andrew Feldman are complete; balances and unit counts will be added when the check is finished.

−50Kgifted (net of own trusts)

−107Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
1,150,000	$2.40	May 13, 2029	$221M
525,000	$2.72	Dec 7, 2030	$101M
12,674	$7.89	Jan 11, 2032	$2.4M
87,326	$5.02	Feb 13, 2033	$16.6M
800,000	$5.48	Feb 6, 2034	$152M

Estimate: options held × ($194.92 − strike price), using the most recent insider trade price on Form 4 (Sep 29, 2026), not a market close.

Lior Susan

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. See the filing Sales and other transactions for Lior Susan are complete.

Director

n/a

0

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Lior Susan

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Lior Susan are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Sean Lie

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Sean Lie are complete.

Chief Technology Officer

n/a

−931K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Sean Lie

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Sean Lie are complete; balances and unit counts will be added when the check is finished.

−265Kgifted (net of own trusts)

−96Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
41,764	$2.40	May 13, 2029	$8.0M
36,764	$2.72	Dec 7, 2030	$7.1M
12,674	$7.89	Jan 11, 2032	$2.4M
32,420	$5.02	Feb 13, 2033	$6.2M
172,146	$5.48	Feb 6, 2034	$32.6M

Estimate: options held × ($194.92 − strike price), using the most recent insider trade price on Form 4 (Sep 29, 2026), not a market close.

Robert Komin Jr.

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Robert Komin Jr. are complete.

Chief Financial Officer

n/a

−33K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Robert Komin Jr.

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Robert Komin Jr. are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
18,248	$5.48	Mar 12, 2034	$3.5M

Estimate: options held × ($194.92 − strike price), using the most recent insider trade price on Form 4 (Sep 29, 2026), not a market close.

Paul Auvil III

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Paul Auvil III are complete.

Director

n/a

0

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Paul Auvil III

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Paul Auvil III are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Yagnesh Patel

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Yagnesh Patel are complete.

Chief Accounting Officer

n/a

−16K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Yagnesh Patel

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Yagnesh Patel are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−19Kwithheld by the company for taxes

Dhiraj Mallick

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Dhiraj Mallick are complete.

Chief Operating Officer

n/a

−514K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Dhiraj Mallick

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Dhiraj Mallick are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−491Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
91,370	$0.98	Jul 16, 2028	$17.7M
200,000	$2.72	Jul 6, 2030	$38.4M
100,000	$2.89	Mar 14, 2031	$19.2M
300,000	$6.47	Aug 22, 2032	$56.5M
200,000	$5.02	Feb 13, 2033	$38.0M
105,000	$5.02	Jul 31, 2033	$19.9M

Estimate: options held × ($194.92 − strike price), using the most recent insider trade price on Form 4 (Sep 29, 2026), not a market close.

Elena Donio

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Elena Donio are complete.

Director

n/a

0

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Elena Donio

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Elena Donio are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Eric Vishria

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Eric Vishria are complete.

Director

n/a

−68K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Eric Vishria

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Eric Vishria are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Steven Vassallo

!

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Steven Vassallo are complete.

Director

n/a

−100K

n/a

n/a

Vesting, gifts, unvested awards and holding lines for Steven Vassallo

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Steven Vassallo are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Holdings and share of stake for Cerebras Systems Inc. are being verified, so no balances, unit counts or percentages are shown. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings.

What explains the selling$408M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $408M across 1,981,999 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

Disclosed plan · $346M · 85%

15%

The lighter segment is sales with no plan disclosed in the filing ($62.4M), including tax-related sales outside a plan.

No plan disclosed · $36.3M

Sales with no 10b5-1 plan and no tax reference in the filing. $21.4M of it is Steven Vassallo. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: Steven Vassallo, Sep 4, 2026

Taxes

$26.1M of sales (6.4%) cite tax obligations in their footnotes. Separately, 713,377 shares ($132M) were withheld by the company for taxes, which isn't a market sale. Example: Dhiraj Mallick, Aug 18, 2026

Charitable gifts · 315K shares

Gifts the filings describe as charitable. Gifts are not sales and are not included in the sale totals.

Seller	Shares sold	Proceeds	Under a disclosed plan	Share of total	Sales dates
Sean Lie Chief Technology Officer	931K	$194M	97%	47%	Jun 25, 2026 to Sep 25, 2026
Dhiraj Mallick Chief Operating Officer	514K	$104M	78%	25%	Jun 25, 2026 to Sep 29, 2026
Andrew Feldman CEO, President, Director	320K	$64.3M	86%	16%	Jun 25, 2026 to Sep 4, 2026
Steven Vassallo Director	100K	$21.4M	0%	5%	Aug 14, 2026 to Sep 4, 2026
Eric Vishria Director	68K	$15.7M	100%	4%	Aug 17, 2026 to Aug 17, 2026
Robert Komin Jr. Chief Financial Officer	33K	$6.6M	100%	2%	Sep 29, 2026 to Sep 29, 2026
Yagnesh Patel Chief Accounting Officer	16K	$3.0M	9%	0.7%	Jun 25, 2026 to Sep 28, 2026

Sales by month

Month	Sale proceeds	Disclosed plan	To cover taxes	No plan disclosed
Oct 2025	$0	$0	$0	$0
Nov 2025	$0	$0	$0	$0
Dec 2025	$0	$0	$0	$0
Jan 2026	$0	$0	$0	$0
Feb 2026	$0	$0	$0	$0
Mar 2026	$0	$0	$0	$0
Apr 2026	$0	$0	$0	$0
May 2026	$0	$0	$0	$0
Jun 2026	$20.7M	$0	$6.9M	$13.8M
Jul 2026	$0	$0	$0	$0
Aug 2026	$245M	$214M	$19.2M	$12.0M
Sep 2026	$142M	$132M	$0	$10.5M
Oct 2026	$0	$0	$0	$0

Known gaps and uncertainty10 officers and directors not confirmed

Holdings and share of stake are being verified. Balances, unit counts and every share-of-stake figure for Cerebras Systems Inc. are held back until that check is finished. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings and are complete.

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology74 filings on record, 74 filed in the 12-month period, and how we read them

All 74 Forms 3, 4 and 5 on record for Cerebras Systems Inc. (SEC CIK 2021728), filed from May 13, 2026 to Oct 7, 2026; 74 of them were filed in the 12 months this page covers, retrieved from SEC EDGAR on Oct 13, 2026. Prices are the ones reported in each filing, often weighted averages.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Spotted something wrong on this page? Report an error. We check every report against the SEC filing and list what we fix in the corrections log.