BOLD

Boundless Bio, Inc.$2.45-0.03 (-1.21%)

Prev Close$2.48·MCap$25.5M·P/E—·Vol42.0K·Yield—

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Buys (12M)

$1.94M

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Sells (12M)

$134.0K

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Net Activity

Net Buyer

$1.81M

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Active Insiders

last 12 mo

Over the past 12 months, insider activity at Boundless Bio, Inc. (BOLD) has been dominated by buying, with 9 insider purchases totaling $1.94M and 3 insider sales totaling $134.0K. The most recent insider transaction was by TANG KEVIN (10 percent owner), who purchased $25.7K worth of shares on Oct 29, 2026. Boundless Bio, Inc. operates in the Healthcare sector, within the Biotechnology industry, with a market cap of $25.5M.

BOLD Insider Trading Activity

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Oct 29, 2026	TANG KEVIN	10 percent owner	Buy	10,707	$2.40	$25.7K	3,022,456
Oct 26, 2026	TANG KEVIN	10 percent owner	Buy	21,640	$2.39	$51.6K	3,011,749
Oct 20, 2026	TANG KEVIN	10 percent owner	Buy	149,474	$2.34	$349.6K0.7% OS	2,990,109
Aug 28, 2026	TANG KEVIN	10 percent owner	Sell	18,300	$2.97	$54.4K	2,840,635
Jul 21, 2026	TANG KEVIN	10 percent owner	Buy	4,863	$2.44	$11.9K	2,858,935
Jul 16, 2026	TANG KEVIN	10 percent owner	Buy	63,969	$2.43	$155.6K	2,854,072
Jul 13, 2026	TANG KEVIN	10 percent owner	Buy	91,585	$2.42	$222.1K	2,790,103
Jul 8, 2026	TANG KEVIN	10 percent owner	Buy	57,210	$2.48	$141.9K	2,698,518
Jul 6, 2026	ARCH Venture Fund IX, L.P.	10 percent owner	Sell	16,000	$2.49	$39.8K	0Exit
Jul 6, 2026	CRANDELL KEITH	10 percent owner	Sell	16,000	$2.49	$39.8K	0Exit
Jul 2, 2026	TANG KEVIN	10 percent owner	Buy	107,463	$2.50	$268.9K	2,641,308
Jun 29, 2026	TANG KEVIN	10 percent owner	Buy	286,333	$2.50	$714.8K1.3% OS	2,533,845
Apr 2, 2024	Burow Kristina	Director	Buy	200,000	$16.00	$3.20M0.9% OS	0

BOLD Insider Buying Activity

The following table shows recent insider purchases of Boundless Bio, Inc. (BOLD) stock reported via SEC Form 4 filings.

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Oct 29, 2026	TANG KEVIN	10 percent owner	Buy	10,707	$2.40	$25.7K	3,022,456
Oct 26, 2026	TANG KEVIN	10 percent owner	Buy	21,640	$2.39	$51.6K	3,011,749
Oct 20, 2026	TANG KEVIN	10 percent owner	Buy	149,474	$2.34	$349.6K0.7% OS	2,990,109
Jul 21, 2026	TANG KEVIN	10 percent owner	Buy	4,863	$2.44	$11.9K	2,858,935
Jul 16, 2026	TANG KEVIN	10 percent owner	Buy	63,969	$2.43	$155.6K	2,854,072
Jul 13, 2026	TANG KEVIN	10 percent owner	Buy	91,585	$2.42	$222.1K	2,790,103
Jul 8, 2026	TANG KEVIN	10 percent owner	Buy	57,210	$2.48	$141.9K	2,698,518
Jul 2, 2026	TANG KEVIN	10 percent owner	Buy	107,463	$2.50	$268.9K	2,641,308
Jun 29, 2026	TANG KEVIN	10 percent owner	Buy	286,333	$2.50	$714.8K1.3% OS	2,533,845
Apr 2, 2024	Burow Kristina	Director	Buy	200,000	$16.00	$3.20M0.9% OS	0

BOLD Insider Selling Activity

The following table shows recent insider sales of Boundless Bio, Inc. (BOLD) stock reported via SEC Form 4 filings.

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Aug 28, 2026	TANG KEVIN	10 percent owner	Sell	18,300	$2.97	$54.4K	2,840,635
Jul 6, 2026	ARCH Venture Fund IX, L.P.	10 percent owner	Sell	16,000	$2.49	$39.8K	0Exit
Jul 6, 2026	CRANDELL KEITH	10 percent owner	Sell	16,000	$2.49	$39.8K	0Exit