144 ·Filed May 7, 2026
Form 144 — notice of proposed sale of securities
Actionable Insight • Neutral
Monitor for further insider selling trends; current pattern suggests routine diversification by a former officer, not a material signal. No immediate trading action warranted.
Final — all horizons settled through T+60d ⚠ clustered
MBX ▲ +85.57% at T+60d
NEUTRAL call +85.57% · α vs SPY +81.73% · entry $34.71 → $64.41
T+1d
+18.02%
call +18.02% · α +17.19%
$40.97
settled 6mo ago
T+5d
+8.04%
call +8.04% · α +6.53%
$37.50
settled 6mo ago
T+20d
-13.43%
call -13.43% · α -16.56%
$30.05
settled 5mo ago
T+60d
+85.57%
call +85.57% · α +81.73%
$64.41
settled 3mo ago
Price Chart
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Executive Summary
Former officer Richard B. Bartram filed Form 144 to sell 10,000 MBX shares (~$322,000), part of a consistent selling pattern over recent months. The small size relative to market cap ($1.5B) and former officer status make this a routine portfolio move with limited price impact.
Key Facts
- Insider: Richard B. Bartram, former officer of MBX Biosciences.
- Proposed sale: 10,000 shares, estimated value $322,050.
- Prior sales: ~26,484 shares sold between March and May 2026.
- Sale represents ~0.02% of shares outstanding (47.6M shares).
- Company market cap: ~$1.5B.
Financial Impact
$322,050 proposed sale, cumulative ~$1.1M sold in last 2 months.
insider ownershipdilution
Risk Factors
- Continued insider selling could indicate lack of confidence, though current scale is minimal.
- No other material company events in filing to assess broader context.
Market Snapshot
Exchange
Nasdaq
Sector
Pharmaceutical Preparations
Analyst Consensus
87% bullish (15 analysts)
Investment Themes
Documents Analyzed
This report is based on 3 SEC documents filed with EDGAR.
| Document | Accession Number |
|---|---|
| 144 Filing (Primary) | 0001959173-26-003370 |
| Document: 0001959173-26-003370-index.html | 0001959173-26-003370 |
| Document: 0001959173-26-003370.txt | 0001959173-26-003370 |
27 reports for MBX
70% Hit rate @ T+1 Went positive at some point 8 of 10 best @ T+60▲ +85.57%
Filters
Rows
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 22, 2026 4d ago | 3 | $50.46 $48.50 | ▼ −3.88% | ▼ −3.36% | $50.29 (−0.34%) |
Oct 22, 2026 4d ago | 8-K | $50.46 $48.50 | ▼ −3.88% | ▼ −3.36% | $50.29 (−0.34%) |
Aug 27, 2026 8w ago | Press Release | $66.39 $63.00 | ▼ −5.11% | ▼ −4.88% | $50.29 (−24.25%) |
Aug 17, 2026 10w ago | 144 | $68.25 $66.52 | ▼ −2.53% | ▼ −1.86% | $50.29 (−26.32%) |
Aug 6, 2026 11w ago | 8-K | $67.11 $67.82 | ▲ +1.06% | ▲ +0.45% | $50.29 (−25.06%) |
Jun 12, 2026 19w ago | 8-K | $35.51 $38.98 | ▲ +9.77% | ▲ +8.01% | $50.29 (+41.62%) |
Jun 12, 2026 19w ago | Press Release | $35.51 $38.98 | ▲ +9.77% | ▲ +8.01% | $50.29 (+41.62%) |
Jun 11, 2026 19w ago | Institutional Cluster | $37.25 $35.51 | ▼ −4.67% | ▼ −5.21% | $50.29 (+35.01%) |
Jun 11, 2026 19w ago | Institutional Cluster | $37.25 $35.51 | ▼ −4.67% | ▼ −5.21% | $50.29 (+35.01%) |
Jun 10, 2026 19w ago | 144 | $30.99 $37.25 | ▲ +20.20% | ▲ +18.50% | $50.29 (+62.28%) |
Showing 10 of 27
US Market Status
Market Closed — Opens Tue (16h 38m)
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