Cerebras Systems CTO Sean Lie Sells $6.95M in Class A Shares Under 10b5-1 Plan

Executive Summary

On October 27, 2026, Sean Lie, Chief Technology Officer of Cerebras Systems Inc. (NASDAQ: CBRS), executed open-market sales totaling 60,000 shares of Class A Common Stock for aggregate gross proceeds of approximately $6.95 million. The transactions were conducted pursuant to a pre-established Rule 10b5-1 trading plan adopted on May 20, 2026. Additionally, the insider transferred 18,000 shares as a charitable gift to a donor-advised fund.

Transaction Details

• Stock Option Exercises & Conversions: Mr. Lie exercised options to acquire 32,023 shares of Class B Common Stock (28,898 options at $5.48 and 3,125 options at $5.02) and subsequently converted those 32,023 Class B shares into Class A Common Stock on a 1:1 basis.
• Charitable Gift: Transferred 18,000 Class A shares at $0 to a 501(c)(3) donor-advised fund.
• Open-Market Sales (executed in multiple tranches):
  • 14,500 shares at a weighted-average price of $116.82 ($1,693,890.00)
  • 45,400 shares at a weighted-average price of $115.46 ($5,241,884.00)
  • 100 shares at $113.92 ($11,392.00)
  • Total Sold: 60,000 shares for $6,947,166.00 at an effective weighted-average price of $115.79 per share.

Holdings Analysis

Following these transactions, Mr. Lie retains substantial direct ownership:

• Direct Class A Common Stock: 263,592 shares
• Direct Class B Common Stock: 7,582,992 shares
• Indirect Class B Common Stock (via Spouse): 180,600 shares

The 60,000 shares sold represent less than 1% of his combined Class A and Class B holdings, indicating strong retained alignment with long-term company performance.

Market Significance

Ranked Medium. While the transaction value exceeds $6.9 million, the trades were executed under a Rule 10b5-1 plan established five months prior, accompanied by option exercises and a charitable gift. Given the modest fraction of the insider's total ownership represented by the sale, the trading activity reflects programmed liquidity and portfolio diversification rather than an unscripted sentiment shift.