BOLD

Boundless Bio, Inc.

Insider trading activity for Boundless Bio, Inc., straight from SEC Form 4 filings. Net figures below count open-market buys and sales only — grants, option exercises and tax withholding are excluded because they are compensation, not decisions to trade.

Past 3 months

+$404K

net buying

Bought(13 · 1 insiders): $458.4K
Sold(1 · 1 insiders): $54.4K

Past 6 months

+$1.8M

net buying

Bought(35 · 1 insiders): $2M
Sold(3 · 3 insiders): $134K

Past 12 months

+$1.8M

net buying

Bought(35 · 1 insiders): $2M
Sold(3 · 3 insiders): $134K

Transaction history

The 57 most recent Form 4 transactions.

Open in screener →

Insider transactions, newest first: date, security, transaction type, size and a link to the filing each row came from.
Date	Insider	Role	Type	Shares	Price	Value	Δ Own	Filing
Nov 10	Tang Kevin	10% Owner	PBUY	249	$2.40	$598	+<0.1%	Open the original filing on SEC.gov
Nov 6	Tang Kevin	10% Owner	PBUY	1,700	$2.40	$4.1K	+<0.1%	Open the original filing on SEC.gov
Nov 5	Tang Kevin	10% Owner	PBUY	8,390	$2.40	$20.1K	+0.3%	Open the original filing on SEC.gov
Nov 4	Tang Kevin	10% Owner	PBUY	517	$2.40	$1.2K	+<0.1%	Open the original filing on SEC.gov
Nov 3	Tang Kevin	10% Owner	PBUY	2,255	$2.40	$5.4K	+<0.1%	Open the original filing on SEC.gov
Oct 27	Tang Kevin	10% Owner	PBUY	10,707	$2.40	$25.7K	+0.4%	Open the original filing on SEC.gov
Oct 26	Tang Kevin	10% Owner	PBUY	9,606	$2.38	$22.9K	+0.3%	Open the original filing on SEC.gov
Oct 23	Tang Kevin	10% Owner	PBUY	6,234	$2.38	$14.8K	+0.2%	Open the original filing on SEC.gov
Oct 22	Tang Kevin	10% Owner	PBUY	5,800	$2.40	$13.9K	+0.2%	Open the original filing on SEC.gov
Oct 20	Tang Kevin	10% Owner	PBUY	220	$2.37	$521	+<0.1%	Open the original filing on SEC.gov
Oct 19	Tang Kevin	10% Owner	PBUY	18,279	$2.33	$42.6K	+0.6%	Open the original filing on SEC.gov
Oct 19	Tang Kevin	10% Owner	PBUY	12,790	$2.34	$29.9K	+0.4%	Open the original filing on SEC.gov
Oct 16	Tang Kevin	10% Owner	PBUY	118,185	$2.34	$276.6K	+4.2%	Open the original filing on SEC.gov
Aug 26	Tang Kevin	10% Owner	SSELL	18,300	$2.97	$54.4K	-0.6%	Open the original filing on SEC.gov
Jul 21	Tang Kevin	10% Owner	PBUY	2,975	$2.44	$7.3K	+0.1%	Open the original filing on SEC.gov
Jul 20	Tang Kevin	10% Owner	PBUY	1,623	$2.44	$4K	+<0.1%	Open the original filing on SEC.gov
Jul 17	Tang Kevin	10% Owner	PBUY	265	$2.44	$647	+<0.1%	Open the original filing on SEC.gov
Jul 16	Tang Kevin	10% Owner	PBUY	18,491	$2.44	$45.1K	+0.7%	Open the original filing on SEC.gov
Jul 15	Tang Kevin	10% Owner	PBUY	1,600	$2.44	$3.9K	+<0.1%	Open the original filing on SEC.gov
Jul 14	Tang Kevin	10% Owner	PBUY	43,878	$2.43	$106.6K	+1.6%	Open the original filing on SEC.gov
Jul 13	Tang Kevin	10% Owner	PBUY	48,211	$2.42	$116.7K	+1.8%	Open the original filing on SEC.gov
Jul 10	Tang Kevin	10% Owner	PBUY	43,367	$2.43	$105.4K	+1.6%	Open the original filing on SEC.gov
Jul 9	Tang Kevin	10% Owner	PBUY	7	$2.48	$17	0.0%	Open the original filing on SEC.gov
Jul 8	Tang Kevin	10% Owner	PBUY	14,338	$2.46	$35.3K	+0.5%	Open the original filing on SEC.gov
Jul 7	Tang Kevin	10% Owner	PBUY	15,810	$2.48	$39.2K	+0.6%	Open the original filing on SEC.gov
Jul 6	Tang Kevin	10% Owner	PBUY	27,062	$2.49	$67.4K	+1.0%	Open the original filing on SEC.gov
Jul 2	Tang Kevin	10% Owner	PBUY	9,821	$2.49	$24.5K	+0.4%	Open the original filing on SEC.gov
Jul 1	Tang Kevin	10% Owner	PBUY	71,612	$2.49	$178.3K	+2.8%	Open the original filing on SEC.gov
Jul 1	Crandell Keith	10% Owner	MEXER◆	16,000	—	—	—	Open the original filing on SEC.gov
Jul 1	Crandell Keith	10% Owner	SSELL	16,000	$2.49	$39.8K	-100.0%	Open the original filing on SEC.gov
Jul 1	Crandell Keith	10% Owner	MEXER	16,000	$1.03	$16.5K	—	Open the original filing on SEC.gov
Jul 1	ARCH Venture Fund IX,…	10% Owner	MEXER◆	16,000	—	—	—	Open the original filing on SEC.gov
Jul 1	ARCH Venture Fund IX,…	10% Owner	SSELL	16,000	$2.49	$39.8K	-100.0%	Open the original filing on SEC.gov
Jul 1	ARCH Venture Fund IX,…	10% Owner	MEXER	16,000	$1.03	$16.5K	—	Open the original filing on SEC.gov
Jun 30	Tang Kevin	10% Owner	PBUY	100	$2.50	$250	0.0%	Open the original filing on SEC.gov
Jun 30	Tang Kevin	10% Owner	PBUY	25,930	$2.54	$65.9K	+1.0%	Open the original filing on SEC.gov
Jun 29	Tang Kevin	10% Owner	PBUY	777	$2.48	$1.9K	+<0.1%	Open the original filing on SEC.gov
Jun 29	Tang Kevin	10% Owner	PBUY	63,985	$2.47	$158K	+2.6%	Open the original filing on SEC.gov
Jun 26	Tang Kevin	10% Owner	PBUY	134	$2.54	$340	+<0.1%	Open the original filing on SEC.gov
Jun 26	Tang Kevin	10% Owner	PBUY	75,047	$2.55	$191.4K	+3.1%	Open the original filing on SEC.gov
Jun 25	Tang Kevin	10% Owner	PBUY	510	$2.56	$1.3K	+<0.1%	Open the original filing on SEC.gov
Jun 25	Tang Kevin	10% Owner	PBUY★	145,880	$2.48	$361.8K	+6.5%	Open the original filing on SEC.gov
Jun 15	Whiting Nancy	Director	AGRANT◆	32,000	—	—	—	Open the original filing on SEC.gov
Jun 15	Lim Jonathan E	Director	AGRANT◆	48,000	—	—	—	Open the original filing on SEC.gov
Jun 15	Christensen James	Director	AGRANT◆	32,000	—	—	—	Open the original filing on SEC.gov
Jun 15	Lew Jennifer	Director	AGRANT◆	32,000	—	—	—	Open the original filing on SEC.gov
Jan 23	Oien Jessica	See Remarks	AGRANT◆	220,000	—	—	—	Open the original filing on SEC.gov
Jan 23	Hassig Christian	Chief Scientific Officer	AGRANT◆	230,000	—	—	—	Open the original filing on SEC.gov
Jan 23	Doebele Robert	Chief Medical Officer	AGRANT◆	230,000	—	—	—	Open the original filing on SEC.gov
Jan 23	Hornby Zachary	President & CEO	AGRANT◆	600,000	—	—	—	Open the original filing on SEC.gov
Jan 23	Hinkle David A	See Remarks	AGRANT◆	140,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Brennan Christine	Director	AGRANT◆	16,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Christensen James	Director	AGRANT◆	16,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Lew Jennifer	Director	AGRANT◆	16,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Lim Jonathan E	Director	AGRANT◆	24,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Burow Kristina	Director, 10% Owner	AGRANT◆	16,000	—	—	—	Open the original filing on SEC.gov
Jun 23, 2025	Whiting Nancy	Director	AGRANT◆	16,000	—	—	—	Open the original filing on SEC.gov

PBUY$598

Tang Kevin · 10% OwnerNov 10

249 sh @ $2.40 · +<0.1% own

PBUY$4.1K

Tang Kevin · 10% OwnerNov 6

1,700 sh @ $2.40 · +<0.1% own

PBUY$20.1K

Tang Kevin · 10% OwnerNov 5

8,390 sh @ $2.40 · +0.3% own

PBUY$1.2K

Tang Kevin · 10% OwnerNov 4

517 sh @ $2.40 · +<0.1% own

PBUY$5.4K

Tang Kevin · 10% OwnerNov 3

2,255 sh @ $2.40 · +<0.1% own

PBUY$25.7K

Tang Kevin · 10% OwnerOct 27

10,707 sh @ $2.40 · +0.4% own

PBUY$22.9K

Tang Kevin · 10% OwnerOct 26

9,606 sh @ $2.38 · +0.3% own

PBUY$14.8K

Tang Kevin · 10% OwnerOct 23

6,234 sh @ $2.38 · +0.2% own

PBUY$13.9K

Tang Kevin · 10% OwnerOct 22

5,800 sh @ $2.40 · +0.2% own

PBUY$521

Tang Kevin · 10% OwnerOct 20

220 sh @ $2.37 · +<0.1% own

PBUY$42.6K

Tang Kevin · 10% OwnerOct 19

18,279 sh @ $2.33 · +0.6% own

PBUY$29.9K

Tang Kevin · 10% OwnerOct 19

12,790 sh @ $2.34 · +0.4% own

PBUY$276.6K

Tang Kevin · 10% OwnerOct 16

118,185 sh @ $2.34 · +4.2% own

SSELL$54.4K

Tang Kevin · 10% OwnerAug 26

18,300 sh @ $2.97 · -0.6% own

PBUY$7.3K

Tang Kevin · 10% OwnerJul 21

2,975 sh @ $2.44 · +0.1% own

PBUY$4K

Tang Kevin · 10% OwnerJul 20

1,623 sh @ $2.44 · +<0.1% own

PBUY$647

Tang Kevin · 10% OwnerJul 17

265 sh @ $2.44 · +<0.1% own

PBUY$45.1K

Tang Kevin · 10% OwnerJul 16

18,491 sh @ $2.44 · +0.7% own

PBUY$3.9K

Tang Kevin · 10% OwnerJul 15

1,600 sh @ $2.44 · +<0.1% own

PBUY$106.6K

Tang Kevin · 10% OwnerJul 14

43,878 sh @ $2.43 · +1.6% own

PBUY$116.7K

Tang Kevin · 10% OwnerJul 13

48,211 sh @ $2.42 · +1.8% own

PBUY$105.4K

Tang Kevin · 10% OwnerJul 10

43,367 sh @ $2.43 · +1.6% own

PBUY$17

Tang Kevin · 10% OwnerJul 9

7 sh @ $2.48 · 0.0% own

PBUY$35.3K

Tang Kevin · 10% OwnerJul 8

14,338 sh @ $2.46 · +0.5% own

PBUY$39.2K

Tang Kevin · 10% OwnerJul 7

15,810 sh @ $2.48 · +0.6% own

PBUY$67.4K

Tang Kevin · 10% OwnerJul 6

27,062 sh @ $2.49 · +1.0% own

PBUY$24.5K

Tang Kevin · 10% OwnerJul 2

9,821 sh @ $2.49 · +0.4% own

PBUY$178.3K

Tang Kevin · 10% OwnerJul 1

71,612 sh @ $2.49 · +2.8% own

MEXER◆—

Crandell Keith · 10% OwnerJul 1

16,000 sh

SSELL$39.8K

Crandell Keith · 10% OwnerJul 1

16,000 sh @ $2.49 · -100.0% own

MEXER$16.5K

Crandell Keith · 10% OwnerJul 1

16,000 sh @ $1.03

MEXER◆—

ARCH Venture Fund IX,… · 10% OwnerJul 1

16,000 sh

SSELL$39.8K

ARCH Venture Fund IX,… · 10% OwnerJul 1

16,000 sh @ $2.49 · -100.0% own

MEXER$16.5K

ARCH Venture Fund IX,… · 10% OwnerJul 1

16,000 sh @ $1.03

PBUY$250

Tang Kevin · 10% OwnerJun 30

100 sh @ $2.50 · 0.0% own

PBUY$65.9K

Tang Kevin · 10% OwnerJun 30

25,930 sh @ $2.54 · +1.0% own

PBUY$1.9K

Tang Kevin · 10% OwnerJun 29

777 sh @ $2.48 · +<0.1% own

PBUY$158K

Tang Kevin · 10% OwnerJun 29

63,985 sh @ $2.47 · +2.6% own

PBUY$340

Tang Kevin · 10% OwnerJun 26

134 sh @ $2.54 · +<0.1% own

PBUY$191.4K

Tang Kevin · 10% OwnerJun 26

75,047 sh @ $2.55 · +3.1% own

PBUY$1.3K

Tang Kevin · 10% OwnerJun 25

510 sh @ $2.56 · +<0.1% own

PBUY★$361.8K

Tang Kevin · 10% OwnerJun 25

145,880 sh @ $2.48 · +6.5% own

AGRANT◆—

Whiting Nancy · DirectorJun 15

32,000 sh

AGRANT◆—

Lim Jonathan E · DirectorJun 15

48,000 sh

AGRANT◆—

Christensen James · DirectorJun 15

32,000 sh

AGRANT◆—

Lew Jennifer · DirectorJun 15

32,000 sh

AGRANT◆—

Oien Jessica · See RemarksJan 23

220,000 sh

AGRANT◆—

Hassig Christian · Chief Scientific…Jan 23

230,000 sh

AGRANT◆—

Doebele Robert · Chief Medical…Jan 23

230,000 sh

AGRANT◆—

Hornby Zachary · President & CEOJan 23

600,000 sh

AGRANT◆—

Hinkle David A · See RemarksJan 23

140,000 sh

AGRANT◆—

Brennan Christine · DirectorJun 23, 2025

16,000 sh

AGRANT◆—

Christensen James · DirectorJun 23, 2025

16,000 sh

AGRANT◆—

Lew Jennifer · DirectorJun 23, 2025

16,000 sh

AGRANT◆—

Lim Jonathan E · DirectorJun 23, 2025

24,000 sh

AGRANT◆—

Burow Kristina · Director, 10%…Jun 23, 2025

16,000 sh

AGRANT◆—

Whiting Nancy · DirectorJun 23, 2025

16,000 sh

Filing record

How quickly insiders here report their trades. Section 16 allows two business days from the transaction.

All 19 filings we hold were filed within the two-business-day deadline.

Counted in business days from the transaction date, or the deemed execution date where the filing reports one, excluding weekends and federal holidays. How this is measured · All late filings

Insiders at this company

Everyone who has filed a Form 4 for this issuer.

More biotech & pharma companies

Other issuers in the same industry with insider filings on record.

Whole sector →