CBRS insider buying and SEC filings, explained
Cerebras Systems Inc. · CIK 2021728
Tracked: Forms 3/4/5, 8-K, NT · All filings on sec.gov
Insider activity in the last 12 months
Bought
$0
Insiders who bought
0
Sold (not marked 10b5-1)
$17.1M
Planned sales (10b5-1)
$352.9M
Insider purchases and sales, last 12 months
| Traded | Type | What was filed | Source |
|---|---|---|---|
| Oct 27, 2026 | Planned (10b5-1) | Sean Lie (Chief Technology Officer) sold 60,000 shares at about $115.79 ($6.9M), marked as a 10b5-1 plan trade. Holdings down 19% to 263,592 shares. | SEC filing Filed Oct 28, 2026, 6:30 PM ET |
| Sep 29, 2026 | Planned (10b5-1) | Robert Patrick Komin Jr. (CFO) sold 32,500 shares at about $203.53 ($6.6M), marked as a 10b5-1 plan trade. Holdings down 100% to 0 shares. | SEC filing Filed Sep 30, 2026 |
| Sep 29, 2026 | Planned (10b5-1) | Dhiraj Mallick (President / COO) sold 396,000 shares at about $204.04 ($80.8M), marked as a 10b5-1 plan trade. Holdings down 100% to 0 shares. | SEC filing Filed Sep 30, 2026 |
| Sep 28, 2026 | Planned (10b5-1) | Yagnesh Patel (Chief Accounting Officer) sold 1,320 shares at $204.50 ($270K), marked as a 10b5-1 plan trade. Holdings down 8% to 15,356 shares. | SEC filing Filed Sep 30, 2026 |
| Sep 25, 2026 | Planned (10b5-1) | Sean Lie (Chief Technology Officer) sold 120,000 shares at about $208.97 ($25.1M), marked as a 10b5-1 plan trade. Holdings down 28% to 309,569 shares. | SEC filing Filed Sep 28, 2026 |
| Sep 4, 2026 | Sale | Steven Vassallo (Director) sold 50,000 shares indirectly (by trust) at about $210.30 ($10.5M). Holdings by trust down 23% to 171,977 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Sep 8, 2026 |
| Sep 4, 2026 | Planned (10b5-1) | Sean Lie (Chief Technology Officer) sold 53,460 shares at about $210.16 ($11.2M), marked as a 10b5-1 plan trade. Holdings down 13% to 345,569 shares. | SEC filing Filed Sep 8, 2026 |
| Sep 4, 2026 | Planned (10b5-1) | Andrew D. Feldman (CEO and Director) sold 37,441 shares at about $210.46 ($7.9M), marked as a 10b5-1 plan trade. Holdings down 69% to 16,853 shares. | SEC filing Filed Sep 8, 2026 |
| Aug 21, 2026 | Planned (10b5-1) | Andrew D. Feldman (CEO and Director) sold 237,559 shares at about $199.27 ($47.3M), marked as a 10b5-1 plan trade. Holdings down 93% to 16,853 shares. | SEC filing Filed Aug 25, 2026 |
| Aug 20–21, 2026 | Planned (10b5-1) | Sean Lie (Chief Technology Officer) sold 726,540 shares between Aug 20 and Aug 21 at about $207.90 ($151.1M), marked as a 10b5-1 plan trade. Holdings down 66% to 368,926 shares. | SEC filing Filed Aug 21, 2026 |
| Aug 17, 2026 | Planned (10b5-1) | Eric Vishria (Director) sold 68,268 shares indirectly at about $229.77 ($15.7M), marked as a 10b5-1 plan trade. Indirect holdings down 69% to 31,383 shares. | SEC filing Filed Aug 19, 2026 |
| Jun 25–26, 2026 | Sale | Dhiraj Mallick (President / COO) sold 33,314 shares between Jun 25 and Jun 26 at about $178.19 ($5.9M). Holdings down 100% to 0 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 29, 2026 |
| Jun 25–26, 2026 | Sale | Yagnesh Patel (Chief Accounting Officer) sold 4,000 shares between Jun 25 and Jun 26 at about $174.20 ($697K). Holdings down 100% to 0 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 29, 2026 |
66 routine transactions (such as grants, option exercises or tax withholding) are not listed.
Cluster buys
No cluster buys in the last 12 months.
Red flags
No red flags in the last 12 months.
Key events
No key events in the last 12 months.
8-K filings, last 12 months
No 8-K filings in the last 12 months.
Red flags are objective triggers only: the item or form filed, never an opinion.
Follow CBRS in the Insider Ledger app
Get the appA plain-English brief of insider purchases, 8-Ks and red flags at the companies you pick. No account needed.