BOLD Boundless Bio

NASDAQ
$2.66

Boundless Bio (BOLD) 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 Bullish Insiders bought more than they sold over this window — uncommon at any size.
Cluster activity 0 buyers in the last 30 days 1 buyer in the last 90 days 1 seller in the last 90 days
Insiders buying
1
18 transactions
Insiders selling
1
3 transactions
Purchases
$960.3K
389,852 shares
Sales
$134.0K
50,300 shares
Net activity
$826.3K
purchases less sales

How much of that selling was preplanned? 0% planned / 100% discretionary

10b5-1 plan sales $0 0 transactions · 0 shares
Discretionary sales $134.0K 3 transactions · 50,300 shares

Largest single sale: $54.4K.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: July 21, 2026 .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
Sell 18,300 $2.97 $54.4K 2,840,635 −0.6% of holding
Buy 2,975 $2.44 $7.3K 2,858,935
Buy 1,623 $2.44 $4.0K 2,855,960
Buy 265 $2.44 $647 2,854,337
Buy 18,491 $2.44 $45.1K 2,854,072
Buy 1,600 $2.44 $3.9K 2,835,581
Buy 43,878 $2.43 $106.6K 2,833,981
Buy 48,211 $2.42 $116.7K 2,790,103
Buy 43,367 $2.43 $105.4K 2,741,892
Buy 7 $2.48 $17 2,698,525
Buy 14,338 $2.46 $35.3K 2,698,518
Buy 15,810 $2.48 $39.2K 2,684,180
Buy 27,062 $2.49 $67.4K 2,668,370
Buy 9,821 $2.49 $24.5K 2,641,308
Buy 71,612 $2.49 $178.3K 2,631,487
2 fills Sell 32,000 $2.49 $79.7K None left
2 fills Buy 26,030 $2.54 $66.1K 2,559,875
2 fills Buy 64,762 $2.47 $160.0K 2,533,845

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.