The sale is small relative to market cap and tied to vesting, not discretionary. Monitor for any subsequent Form 4 filings to confirm execution, but this filing alone does not signal insider concern.
Price Chart
Executive Summary
Mark Sullivan, an officer of Definium Therapeutics, filed a Form 144 on September 25, 2026, indicating intent to sell 14,051 shares of common stock, with an approximate market value of $516,093. The shares are from restricted stock vesting under a registered plan, and the filing is a routine advance notice of a planned sale by an insider.
Key Facts
- Insider: Mark Sullivan (Officer)
- Shares to be sold: 14,051
- Estimated value: $516,093
- Sale reason: Restricted Stock Vesting Under a Registered Plan
- Filing date: September 25, 2026
- Company market cap: ~$134.4 million (based on filing's outstanding shares value)
Financial Impact
Sale of 14,051 shares worth ~$516,093, representing about 0.01% of the company's market cap (~$134M).
Risk Factors
- Insider selling may be perceived negatively by the market, though the amount is small.
Investment Themes
Documents Analyzed
This report is based on 3 SEC documents filed with EDGAR.
| Document | Accession Number |
|---|---|
| 144 Filing (Primary) | 0001950047-26-009823 |
| Document: 0001950047-26-009823-index.html | 0001950047-26-009823 |
| Document: 0001950047-26-009823.txt | 0001950047-26-009823 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Sep 29, 2026 4w ago | Insider Cluster | $38.06 $35.09 | ▲ +7.80% | ▲ +9.72% | $37.96 (+0.26%) |
Sep 25, 2026 4w ago | 144 | $38.41 $36.23 | ▼ −5.68% | ▼ −6.88% | $37.96 (−1.17%) |
Sep 25, 2026 4w ago | 144 | $38.41 $36.23 | ▼ −5.68% | ▼ −6.88% | $37.96 (−1.17%) |
Sep 25, 2026 4w ago | 144 | $38.41 $36.23 | ▼ −5.68% | ▼ −6.88% | $37.96 (−1.17%) |
Sep 14, 2026 6w ago | 8-K | $40.25 $39.28 | ▼ −2.41% | ▼ −2.52% | $37.96 (−5.69%) |
Aug 12, 2026 11w ago | 8-K | $42.79 $45.82 | ▲ +7.08% | ▲ +7.53% | $37.96 (−11.29%) |
Aug 9, 2026 11w ago | Institutional Cluster | $45.15 $45.26 | ▲ +0.24% | ▲ +0.29% | $37.96 (−15.92%) |
Jun 25, 2026 18w ago | 144 | $44.95 $44.19 | ▼ −1.69% | ▼ −3.86% | $37.96 (−15.55%) |
Jun 25, 2026 18w ago | 144 | $44.95 $44.19 | ▼ −1.69% | ▼ −3.86% | $37.96 (−15.55%) |
Jun 24, 2026 18w ago | 8-K | $44.79 $43.40 | ▲ +3.10% | ▲ +4.66% | $37.96 (+15.25%) |
US Market Status
Subscribe to SecBot
Get Real-Time SEC Filing Intelligence
Comprehensive SEC filing analysis delivered the moment filings hit EDGAR. Sentiment scoring, impact analysis, and actionable insights for every material event.
Create a free account Live analysis, Telegram alerts, watchlists and the MCP server for subscribers