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BOLD

Boundless Bio (BOLD) stock: insider trades, news & valuation

Net buying
Close · Oct 9, 2026 $2.53 -1.9% on the day +97.7% over 12 months 52-week range $1.05 – $3.00

Share price and insider trades

BOLD closeInsider buyInsider sale
1234NovDecJan 2026FebMarAprMayJunJulAugSepOctBought $17 on 2026-07-09 · Kevin TangBought $647 on 2026-07-17 · Kevin TangBought $3,904 on 2026-07-15 · Kevin TangBought $3,960 on 2026-07-20 · Kevin TangBought $7,259 on 2026-07-21 · Kevin TangBought $24,454 on 2026-07-02 · Kevin TangBought $35,271 on 2026-07-08 · Kevin TangBought $39,209 on 2026-07-07 · Kevin TangBought $45,118 on 2026-07-16 · Kevin TangSold $54,351 on 2026-08-26 · Tang Capital Management LlcBought $66,112 on 2026-06-30 · Kevin TangBought $67,384 on 2026-07-06 · Kevin TangSold $79,680 on 2026-07-01 · Arch Venture Partners Ix, L.P., Steven GillisBought $105,382 on 2026-07-10 · Kevin TangBought $106,624 on 2026-07-14 · Kevin TangBought $116,671 on 2026-07-13 · Kevin TangBought $159,970 on 2026-06-29 · Kevin TangBought $178,314 on 2026-07-01 · Kevin TangBought $191,710 on 2026-06-26 · Kevin TangBought $363,088 on 2026-06-25 · Kevin Tang
Bought, 12 months$1.5M
Sold, 12 months$134K
Insiders buying1
Insiders selling3

Boundless Bio insider trading at a glance (Oct 9, 2026): in the past 12 months, 1 insider bought $1.5M and 3 sold $134K of BOLD stock on the open market.

BOLD insider buying and selling by quarter

Open-market purchases (green, above the line) and sales (red, below), by trade date.

Q2 2026: $781K bought (8 trades)$781KQ2 2026Q3 2026: $734K bought (14 trades)$734KQ3 2026: $134K sold (3 trades)Q3 2026Q4 2026
QuarterBoughtPurchasesSoldSales
Q4 2026—0—0
Q3 2026$734K14$134K3
Q2 2026$781K8—0

Valuation, profit and volume

P/E (trailing)n/aSector median —
Market value— 
Profit margin—Revenue growth —
Volume vs. 50-day0.8×Last 5 sessions
Insiders' paper profit+$32KOn all tracked purchases +2.1%

Summary

Over the past 12 months, 1 Boundless Bio, Inc. insider reported open-market purchases totaling $1.5M, while 3 insiders reported sales totaling $134K. Among insiders with enough purchase history to measure, Kevin Tang (10% Owner) has the highest Insider Score at 50. 0 of 3 recorded sales were made under pre-scheduled Rule 10b5-1 trading plans, which are usually less informative than discretionary sales.

Insider transactions

Open-market purchases and sales.

Filed Insider Type Shares Price Value Since Score
Aug 28SEC Tang Capital Management Llc10% Owner Sell 18,3002,840,635 held (−1%) $2.97 $54K -14.8% —
Jul 21SEC Kevin Tang10% Owner Buy 2,9752,858,935 held (+0%) $2.44 $7K +3.7% 50
Jul 21SEC Kevin Tang10% Owner Buy 1,6232,855,960 held (+0%) $2.44 $4K +3.7% 50
Jul 21SEC Kevin Tang10% Owner Buy 2652,854,337 held (+0%) $2.44 $647 +3.7% 50
Jul 16SEC Kevin Tang10% Owner Buy 43,8782,833,981 held (+2%) $2.43 $107K +4.1% 50
Jul 16SEC Kevin Tang10% Owner Buy 18,4912,854,072 held (+1%) $2.44 $45K +3.7% 50
Jul 16SEC Kevin Tang10% Owner Buy 1,6002,835,581 held (+0%) $2.44 $4K +3.7% 50
Jul 13SEC Kevin Tang10% Owner Buy 48,2112,790,103 held (+2%) $2.42 $117K +4.5% 50
Jul 13SEC Kevin Tang10% Owner Buy 43,3672,741,892 held (+2%) $2.43 $105K +4.1% 50
Jul 13SEC Kevin Tang10% Owner Buy 72,698,525 held (+0%) $2.48 $17 +2.0% 50
Jul 8SEC Kevin Tang10% Owner Buy 27,0622,668,370 held (+1%) $2.49 $67K +1.6% 50
Jul 8SEC Kevin Tang10% Owner Buy 15,8102,684,180 held (+1%) $2.48 $39K +2.0% 50
Jul 8SEC Kevin Tang10% Owner Buy 14,3382,698,518 held (+1%) $2.46 $35K +2.8% 50
Jul 6SEC Arch Venture Partners Ix, L.P.10% Owner Sell 16,000 $2.49 $40K +1.6% —
Jul 6SEC Steven Gillis10% Owner Sell 16,000 $2.49 $40K +1.6% —
Jul 2SEC Kevin Tang10% Owner Buy 71,6122,631,487 held (+3%) $2.49 $178K +1.6% 50
Jul 2SEC Kevin Tang10% Owner Buy 25,9302,559,775 held (+1%) $2.54 $66K -0.4% 50
Jul 2SEC Kevin Tang10% Owner Buy 9,8212,641,308 held (+0%) $2.49 $24K +1.6% 50
Jul 2SEC Kevin Tang10% Owner Buy 1002,559,875 held (+0%) $2.50 $250 +1.2% 50
Jun 29SEC Kevin Tang10% Owner Buy 145,8802,393,392 held (+6%) $2.48 $362K +2.0% 50
Jun 29SEC Kevin Tang10% Owner Buy 75,0472,468,949 held (+3%) $2.55 $191K -0.8% 50
Jun 29SEC Kevin Tang10% Owner Buy 63,9852,533,068 held (+3%) $2.47 $158K +2.4% 50
Jun 29SEC Kevin Tang10% Owner Buy 7772,533,845 held (+0%) $2.48 $2K +2.0% 50
Jun 29SEC Kevin Tang10% Owner Buy 5102,393,902 held (+0%) $2.56 $1K -1.2% 50
Jun 29SEC Kevin Tang10% Owner Buy 1342,469,083 held (+0%) $2.54 $340 -0.4% 50

Insiders at Boundless Bio, Inc.

InsiderBoughtSoldLast filingScore
Kevin Tang10% Owner $1.5M — Jul 21, 2026 50
Tang Capital Management Llc10% Owner — $54K Aug 28, 2026 —
Arch Venture Partners Ix, L.P.10% Owner — $40K Jul 6, 2026 —
Steven Gillis10% Owner — $40K Jul 6, 2026 —

BOLD stock: common questions

Are Boundless Bio, Inc. insiders buying BOLD stock?

In the past 12 months, 1 insiders reported open-market purchases of BOLD worth $1.5M. The latest was 10% Owner Kevin Tang bought $7K of BOLD at $2.44.

Are Boundless Bio, Inc. insiders selling BOLD stock?

3 insiders reported sales worth $134K over the same period.

Where does this data come from?

Every transaction comes from Form 4 filings that insiders must submit to the SEC within two business days of a trade. We pull them from SEC EDGAR every night.

What is BOLD's 52-week range?

Over the past year BOLD has traded between $1.05 and $3.00. It last closed at $2.53 on Oct 9, 2026.