C3.ai Chairman Thomas Siebel Has Sold $396 Million Across Two Tech Companies Over 565 Transactions
Thomas Siebel, the billionaire who built and sold Siebel Systems to Oracle, has now filed 565 insider transactions totaling $396 million — including recent exercise-and-sell activity at C3.ai in early 2026.
Thomas Siebel, the tech billionaire who sold Siebel Systems to Oracle for $5.8 billion, has filed 565 insider transactions totaling $396 million in career stock sales — and he’s still actively selling shares of his current company, C3.ai (AI), as recently as February 2026.
The Numbers
| Metric | Value |
|---|---|
| Career Sell Value | $396.1M |
| Total Transactions | 565 |
| Last Transaction | 2026-02-03 |
| Shares Remaining | 747,882 (AI direct) |
Recent Activity
| Date | Type | Shares | Price | Est. Value |
|---|---|---|---|---|
| 2026-02-02 | Sell | 27,605 | $10.81 | $298,422 |
| 2026-01-13 | Sell | 309,589 | $13.52 | $4,185,643 |
| 2026-01-13 | Sell | 212,586 | $13.52 | $2,874,163 |
| 2025-12-17 | Sell | 140,768 | $14.22 | $2,001,721 |
Siebel’s recent activity follows a consistent pattern: exercise stock options at the $2.04 strike price, then sell the resulting shares at market prices. In January 2026, he sold over 522,000 shares in a single day for approximately $7.1 million at $13.52 per share. By February, he was selling smaller lots at $10.81 — a 20% price decline in just three weeks.
What It Means
Siebel founded Siebel Systems in 1993, grew it into the dominant CRM software company, and sold it to Oracle in 2006 for $5.8 billion. He then founded C3.ai in 2009, taking it public in December 2020. As Executive Chairman and 10% owner, his insider filings span two companies and two eras of enterprise software — from CRM to AI.
C3.ai has been a volatile investment since its IPO. The stock debuted above $100, crashed to below $10, and has oscillated between $10-40 as the AI hype cycle ebbs and flows. Siebel’s exercise-and-sell pattern at $10-14 per share in early 2026 — well below the IPO price — suggests he’s monetizing options as they vest rather than timing the market. With 747,882 direct shares remaining, his position is worth approximately $8 million at current prices — modest for a billionaire, reflecting extensive prior liquidation.
What to Watch
- Whether Siebel continues exercising options at $2.04 and selling at market prices in the $10-14 range
- C3.ai’s ability to convert AI hype into sustained enterprise revenue growth
- Siebel’s remaining direct position of 747K shares — at recent selling rates, this could be substantially reduced within 2026
- Any changes in Siebel’s 10% beneficial ownership threshold, which triggers additional SEC reporting requirements
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