Cerebras (CBRS) CTO Lie Sean Sells Shares

What Happened
Lie Sean, Chief Technology Officer of Cerebras Systems (CBRS), executed large option/derivative conversions and sold common stock in open-market transactions on August 20–21, 2026. The filing shows he converted/exercised roughly 713,091 derivative/Class B shares into Class A common stock (696,798 on 8/20 and 16,293 on 8/21) and sold 726,540 shares across multiple trades at prices between about $203.78 and $212.64, generating approximately $151.05 million in proceeds. He also transferred (gifted) 213,074 shares to a donor-advised fund (no cash proceeds).

Key Details

• Transaction dates: Aug 20–21, 2026. Filing date: Aug 21, 2026 (timely).
• Open-market sales: 726,540 shares sold for total proceeds ≈ $151,050,463 (individual trades ranged roughly $203.78–$212.64).
• Gift: 213,074 shares transferred to a donor-advised fund (reported as a gift; $0 proceeds).
• Derivative activity: ~713,091 shares acquired via exercise/conversion of derivatives/options (reported at $0 cash cost) before many were sold. These were conversions of Class B to Class A common stock and option exercises.
• Plan/footnotes: Sales were made under a Rule 10b5-1 trading plan adopted May 20, 2026 (F3). Class B shares are convertible into Class A at the reporting person’s election (F1). Weighted-average sale prices for grouped trades are noted in the filing (F4–F14).
• Shares owned after transaction: Not specified in the provided summary of the filing.

Context and what this means for investors

• Many shares were acquired via exercise/conversion and then sold the same period — effectively a cashing-out of vested/convertible positions rather than open-market purchases (not a bullish purchase signal).
• The 213,074-share gift to a donor-advised fund is a charitable transfer and does not directly signal market sentiment.
• Use of a 10b5-1 plan indicates these sales were pre-arranged and may have occurred according to a schedule or formula set before the trades.
• All derivative exercises/conversions reported $0 cash consideration in the filing (typical for option exercises/stock-class conversions); several footnotes explain weighted-average pricing across grouped trades if you need per-lot detail.