MBX MBX Biosciences, Inc.

BEARISH Impact: 5/10 144
Horizon days Filed May 1, 2026 Processed 1mo ago SEC 0001959173-26-003192
Form 144 — notice of proposed sale of securities
Latest settled — T+20d
MBX ▲ +2.92% at T+20d
SHORT call ✗ call lost -2.92% · α vs SPY +2.36% · entry $29.78 → $30.65
Next anchor: T+60d in 7w
Last close $29.00 (close Jun 8) · +2.62% from $29.78 entry (call sign-flipped)
Entry anchored
May 1, 02:57 PM ET
via Databento tick
T+1d
-1.14%
call +1.14% · α +0.80%
$29.44
settled 5w ago
T+5d
+16.55%
call -16.55% · α -14.21%
$34.71
settled 5w ago
T+20d
+2.92%
call -2.92% · α +2.36%
$30.65
settled 9d ago
T+60d
call — · α —
in 7w

Price Chart

Loading chart...

Executive Summary

Former officer Richard Bartram files Form 144 to sell 5,000 MBX shares (~$159k), adding to 21,484 shares already sold in the prior two months. The consistent insider selling pattern raises concerns about confidence in the company's near-term outlook.

Actionable Insight

The insider's persistent selling warrants caution. Watch for further Form 144 or Form 4 filings; a cessation of sales could stabilize sentiment.

Key Facts

  • Bartram Richard, a former officer, filed Form 144 to sell 5,000 shares of common stock.
  • Estimated market value of proposed sale is $159,000.
  • Sold 21,484 shares in three prior transactions since mid-March 2026.
  • Total insider disposition over ~2 months: 26,484 shares.

Financial Impact

Proposed sale of 5,000 shares valued at ~$159k; cumulative insider sales ~$830k over 2 months.

Risk Factors

  • Continued insider selling may signal weakening confidence in MBX's fundamentals.
  • Potential negative market perception of insider distribution pattern.

Market Snapshot

Exchange
Nasdaq
Sector
Pharmaceutical Preparations
Analyst Consensus
87% bullish (15 analysts)

Documents Analyzed

This report is based on 3 SEC documents filed with EDGAR.

DocumentAccession Number
144 Filing (Primary)0001959173-26-003192
Document: 0001959173-26-003192-index.html0001959173-26-003192
Document: 0001959173-26-003192.txt0001959173-26-003192
17 reports for MBX
Performance horizon
100% Hit rate 3 of 3 directional calls best @ T+5▲ +22.70%May 11, 2026
Filters
Rows
Reports for MBX — sortable, filterable
Type Now
Jun 9, 2026
today
144
BEARISH ★ 5/10
$29.80 awaiting T+5awaiting T+5$29.00 (+2.68%)
Jun 5, 2026
4d ago
8-K
NEUTRAL ★ 3/10
$30.59 awaiting T+5awaiting T+5$29.00 (−5.20%)
May 11, 2026
29d ago
144
BEARISH ★ 5/10
$40.08 $30.98▲ +22.70%▲ +22.62%$29.00 (+27.64%)
May 11, 2026
29d ago
Press Release
MIXED ★ 6/10
$40.08 $30.98▼ −22.70%▼ −22.62%$29.00 (−27.64%)
May 8, 2026
4w ago
144
NEUTRAL ★ 3/10
$40.97 $35.36▼ −13.68%▼ −15.15%$29.00 (−29.21%)
May 7, 2026
4w ago
144
NEUTRAL ★ 2/10
$34.71 $37.50▲ +8.04%▲ +6.53%$29.00 (−16.45%)
May 7, 2026
4w ago
8-K
BULLISH ★ 6/10
$34.71 $37.50▲ +8.04%▲ +6.53%$29.00 (−16.45%)
May 6, 2026
4w ago
144
NEUTRAL ★ 1/10
$32.12 $36.98▲ +15.13%▲ +14.00%$29.00 (−9.71%)
May 6, 2026
5w ago
Insider Cluster
NEUTRAL ★ 2/10
$40.08 $30.98▼ −22.70%▼ −22.62%$29.00 (−27.64%)
May 1, 2026
5w ago
144
BEARISH ★ 5/10
$29.78 $34.71▼ −16.55%▼ −14.21%$29.00 (+2.62%)
Showing 10 of 17

US Market Status

Market Closed — Opens in 7h 8m

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.

Try SecBot Free Coming soon: SecBot Pro with alerts, watchlists, and API access