UPB

Upstream Bio, Inc.$3.19-0.23 (-6.60%)

Prev Close$3.41·MCap$179.1M·P/E—·Vol410.3K·Yield—

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Buys (12M)

$0.00

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Sells (12M)

$104.8K

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Net Activity

Net Seller

$104.8K

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Active Insiders

last 12 mo

Over the past 12 months, insider activity at Upstream Bio, Inc. (UPB) has been exclusively selling, with 0 insider purchases totaling $0.00 and 15 insider sales totaling $104.8K. The most recent insider transaction was by GRAY MICHAEL (officer: CFO and COO), who sold $4.7K worth of shares on Sep 17, 2026. Upstream Bio, Inc. operates in the Healthcare sector, within the Biotechnology industry, with a market cap of $179.1M.

UPB Insider Trading Activity

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Sep 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	853	$5.49	$4.7K	27,942
Sep 17, 2026	Ambrose Allison	officer: General Counsel	Sell	485	$5.49	$2.7K	15,563
Sep 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	700	$5.49	$3.8K	22,901
Sep 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,095	$5.49	$11.5K	68,717
Sep 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	895	$5.49	$4.9K	32,302
Jun 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	853	$6.10	$5.2K	28,795
Jun 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	700	$6.10	$4.3K	23,601
Jun 17, 2026	Ambrose Allison	officer: General Counsel	Sell	477	$6.10	$2.9K	16,048
Jun 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,095	$6.10	$12.8K	70,812
Jun 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	895	$6.10	$5.5K	33,197
Mar 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	852	$9.29	$7.9K	29,648
Mar 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	894	$9.29	$8.3K	32,687
Mar 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	699	$9.29	$6.5K	24,301
Mar 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,093	$9.29	$19.4K	72,907
Mar 17, 2026	Ambrose Allison	officer: General Counsel	Sell	475	$9.29	$4.4K	16,525
Oct 17, 2024	AI Upstream LLC		Buy	1,175,000	$17.00	$19.98M2.2% OS	1,175,000
Oct 17, 2024	Chimovits Erez	Director	Buy	825,000	$17.00	$14.03M1.5% OS	4,554,873

UPB Insider Buying Activity

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

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Oct 17, 2024	AI Upstream LLC		Buy	1,175,000	$17.00	$19.98M2.2% OS	1,175,000
Oct 17, 2024	Chimovits Erez	Director	Buy	825,000	$17.00	$14.03M1.5% OS	4,554,873

UPB Insider Selling Activity

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

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Sep 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	853	$5.49	$4.7K	27,942
Sep 17, 2026	Ambrose Allison	officer: General Counsel	Sell	485	$5.49	$2.7K	15,563
Sep 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	700	$5.49	$3.8K	22,901
Sep 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,095	$5.49	$11.5K	68,717
Sep 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	895	$5.49	$4.9K	32,302
Jun 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	853	$6.10	$5.2K	28,795
Jun 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	700	$6.10	$4.3K	23,601
Jun 17, 2026	Ambrose Allison	officer: General Counsel	Sell	477	$6.10	$2.9K	16,048
Jun 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,095	$6.10	$12.8K	70,812
Jun 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	895	$6.10	$5.5K	33,197
Mar 17, 2026	GRAY MICHAEL	officer: CFO and COO	Sell	852	$9.29	$7.9K	29,648
Mar 17, 2026	Deykin Aaron	officer: Chief Medical Officer	Sell	894	$9.29	$8.3K	32,687
Mar 17, 2026	Houghton Adam	officer: Chief Business Officer	Sell	699	$9.29	$6.5K	24,301
Mar 17, 2026	Sutherland Everett Rand	director, officer: Chief Executive Officer	Sell	2,093	$9.29	$19.4K	72,907
Mar 17, 2026	Ambrose Allison	officer: General Counsel	Sell	475	$9.29	$4.4K	16,525