Monitor upcoming Form 4 filings to confirm whether the sale was executed as planned. Given the seller is a former officer and the volume is small relative to market cap, the impact is likely minimal, but continued insider outflows could signal weakening confidence.
Price Chart
Executive Summary
Richard Bartram, a former officer of MBX Biosciences, filed a Form 144 to report the proposed sale of 11,061 shares of common stock, valued at approximately $330,688, following the exercise of stock options. The sale was reported on April 22, 2026, and is intended to occur on the Nasdaq via cash transactions.
Key Facts
- Reporting owner: Richard Bartram, former officer of MBX Biosciences
- Total shares reported for sale: 11,061 (10,000 on March 16, 2026, and 1,061 on March 25, 2026)
- Approximate value of shares: $330,688 (based on $30.04 average price derived from $300,471 for 10,000 shares and $30,217 for 1,061 shares)
- Shares acquired through exercise of stock options granted in 2022 and 2023
- Sale to be conducted through Fidelity Brokerage Services LLC on Nasdaq
Financial Impact
Approximately $330,688 in potential insider selling, representing a small fraction of MBX's $1.6B market cap
Risk Factors
- Potential perception of insider selling ahead of key clinical or regulatory milestones
- Concentration risk if additional insiders file similar notices
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 3 SEC documents filed with EDGAR.
| Document | Accession Number |
|---|---|
| 144 Filing (Primary) | 0001959173-26-003033 |
| Document: 0001959173-26-003033-index.html | 0001959173-26-003033 |
| Document: 0001959173-26-003033.txt | 0001959173-26-003033 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 22, 2026 5d ago | 3 | $50.46 $48.50 | ▼ −3.88% | ▼ −3.36% | $52.97 (+4.97%) |
Oct 22, 2026 5d ago | 8-K | $50.46 $48.50 | ▼ −3.88% | ▼ −3.36% | $52.97 (+4.97%) |
Aug 27, 2026 8w ago | Press Release | $66.39 $63.00 | ▼ −5.11% | ▼ −4.88% | $52.97 (−20.21%) |
Aug 17, 2026 10w ago | 144 | $68.25 $66.52 | ▼ −2.53% | ▼ −1.86% | $52.97 (−22.39%) |
Aug 6, 2026 11w ago | 8-K | $67.11 $67.82 | ▲ +1.06% | ▲ +0.45% | $52.97 (−21.07%) |
Jun 12, 2026 19w ago | 8-K | $35.51 $38.98 | ▲ +9.77% | ▲ +8.01% | $52.97 (+49.17%) |
Jun 12, 2026 19w ago | Press Release | $35.51 $38.98 | ▲ +9.77% | ▲ +8.01% | $52.97 (+49.17%) |
Jun 11, 2026 19w ago | Institutional Cluster | $37.25 $35.51 | ▼ −4.67% | ▼ −5.21% | $52.97 (+42.20%) |
Jun 11, 2026 19w ago | Institutional Cluster | $37.25 $35.51 | ▼ −4.67% | ▼ −5.21% | $52.97 (+42.20%) |
Jun 10, 2026 19w ago | 144 | $30.99 $37.25 | ▲ +20.20% | ▲ +18.50% | $52.97 (+70.93%) |
US Market Status
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