MBX MBX Biosciences, Inc.

NASDAQ
$59.49

MBX Biosciences, Inc. (MBX) Insider Activity

What the officers, directors and large holders did with their own shares. Only open-market purchases and sales count toward the totals — grants, option exercises and shares withheld for tax are compensation mechanics, not decisions, and they're listed separately below.

Insider signal Bearish Selling ran elevated versus MBX's own trailing one-year pace, with 98% of sale value under a prearranged plan.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 1 seller in the last 90 days
Insiders buying
0
0 transactions
Insiders selling
2
5 transactions
Purchases
$0
0 shares
Sales
$2.7M
71,211 shares
Net activity
-$2.7M
purchases less sales

How much of that selling was preplanned? 98% planned / 2% discretionary

10b5-1 plan sales $2.7M 2 transactions · 70,003 shares
Discretionary sales $49.1K 3 transactions · 1,208 shares

Largest single sale: $2.1M.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: March 13, 2026 , by Hawryluk P. Kent .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
Azoulay Salomon Chief Medical Officer Sell 370 $65.77 $24.3K 14,399 −2.5% of holding
Azoulay Salomon 2 fills Chief Medical Officer Sell 10b5-1 70,003 $38.36 $2.7M 14,769 −82.6% of holding
Hawryluk P. Kent President & CEO Sell 607 $29.54 $17.9K 727,667 −0.1% of holding
Azoulay Salomon Chief Medical Officer Sell 231 $29.54 $6.8K 14,769 −1.5% of holding

Form 4s are due within two business days of a transaction, so this is close to real time — unlike the quarterly 13F data on the Institutional tab. A single large sale often reflects a prearranged 10b5-1 plan rather than a fresh view, so read a pattern of sales rather than any one of them.