Upstream Bio Ownership

Who are the major shareholders and have insiders been buying or selling?

Recent Insider Transactions

NasdaqGS:UPB Recent Insider Transactions by Companies or Individuals
Date	Value	Name	Entity	Shares	Max Price
16 Mar 26	SellUS$6,494	Adam Houghton	Individual	699	US$9.29
16 Mar 26	SellUS$19,444	E. Sutherland	Individual	2,093	US$9.29
16 Mar 26	SellUS$4,413	Allison Ambrose	Individual	475	US$9.29
16 Mar 26	SellUS$7,915	Michael Gray	Individual	852	US$9.29
16 Mar 26	SellUS$8,305	Aaron Deykin	Individual	894	US$9.29

Insider Trading Volume

Insider Buying: UPB insiders have only sold shares in the past 3 months.

Ownership Breakdown

What is the ownership structure of UPB?
Owner Type	Number of Shares	Ownership Percentage
Individual Insiders	190,200	0.341%
Sovereign Wealth Funds	2,882,647	5.17%
Private Companies	7,954,116	14.3%
VC/PE Firms	8,418,457	15.1%
Institutions	36,333,655	65.1%

Dilution of Shares: Shareholders have not been meaningfully diluted in the past year.

Top Shareholders

Top 25 shareholders own 87.28% of the company

Ownership	Name	Shares	Current Value	Change %	Portfolio %
14.9%	FMR LLC	8,101,538	US$65.5m	7.76%	no data
10.5%	OrbiMed Advisors LLC	5,693,589	US$46.0m	0%	0.73%
10.1%	Access Industries Management, LLC	5,494,410	US$44.4m	0%	no data
6.19%	BlackRock, Inc.	3,370,567	US$27.2m	0.78%	no data
5.3%	Norges Bank Investment Management	2,882,647	US$23.3m	0%	no data
5.01%	Decheng Capital LLC	2,724,868	US$22.0m	-13.3%	3.39%
4.52%	Enavate Sciences	2,459,703	US$19.9m	0%	no data
4.03%	HBM Partners Ltd.	2,195,111	US$17.7m	0%	1.6%
3.44%	Vanguard Capital Management, LLC	1,873,574	US$15.1m	0%	no data
1.84%	Y-Intercept (Hong Kong) Limited	1,000,631	US$8.1m	2,050%	0.14%
1.8%	Federated Hermes, Inc.	979,758	US$7.9m	203,000%	0.01%
1.75%	Geode Capital Management, LLC	950,617	US$7.7m	11.6%	no data
1.72%	Millennium Management LLC	937,323	US$7.6m	81.2%	no data
1.61%	SEB Funds AB	878,473	US$7.1m	0%	0.01%
1.59%	Bain Capital Life Sciences Investors, LLC	867,211	US$7.0m	-34.8%	0.48%
1.53%	Woodline Partners LP	831,481	US$6.7m	9.37%	0.02%
1.51%	D. E. Shaw & Co., L.P.	820,480	US$6.6m	2,930%	no data
1.45%	Parkman Healthcare Partners LLC	786,783	US$6.4m	-5.72%	0.64%
1.35%	Samsara BioCapital LLC	736,047	US$5.9m	0%	0.55%
1.35%	Pictet Asset Management Limited	733,431	US$5.9m	-5.14%	no data
1.34%	Vanguard Portfolio Management, LLC	727,711	US$5.9m	0%	no data
1.3%	State Street Global Advisors, Inc.	705,350	US$5.7m	-46.5%	no data
1.18%	HSBC Global Asset Management (UK) Limited	640,326	US$5.2m	0%	no data
1.14%	Qube Research & Technologies Ltd	619,321	US$5.0m	0%	0.01%
0.89%	Morgan Stanley	486,065	US$3.9m	426%	no data

Company Analysis and Financial Data Status

Data	Last Updated (UTC time)
Company Analysis	2026/06/02 22:02
End of Day Share Price	2026/06/02 00:00
Earnings	2026/03/31
Annual Earnings	2025/12/31

Data Sources

The data used in our company analysis is from S&P Global Market Intelligence LLC. The following data is used in our analysis model to generate this report. Data is normalised which can introduce a delay from the source being available.

Package	Data	Timeframe	Example US Source ^*
Company Financials	10 years	Income statement Cash flow statement Balance sheet	SEC Form 10-K SEC Form 10-Q
Analyst Consensus Estimates	+3 years	Forecast financials Analyst price targets	Analyst Research Reports Blue Matrix
Market Prices	30 years	Stock prices Dividends, Splits and Actions	ICE Market Data SEC Form S-1
Ownership	10 years	Top shareholders Insider trading	SEC Form 4 SEC Form 13D
Management	10 years	Leadership team Board of directors	SEC Form 10-K SEC Form DEF 14A
Key Developments	10 years	Company announcements	SEC Form 8-K

^* Example for US securities, for non-US equivalent regulatory forms and sources are used.

Unless specified all financial data is based on a yearly period but updated quarterly. This is known as Trailing Twelve Month (TTM) or Last Twelve Month (LTM) Data. Learn more.

Analysis Model and Snowflake

Details of the analysis model used to generate this report is available on our Github page, we also have guides on how to use our reports and tutorials on Youtube.

Learn about the world class team who designed and built the Simply Wall St analysis model.

Industry and Sector Metrics

Our industry and section metrics are calculated every 6 hours by Simply Wall St, details of our process are available on Github.

Analyst Sources

Upstream Bio, Inc. is covered by 7 analysts. 7 of those analysts submitted the estimates of revenue or earnings used as inputs to our report. Analysts submissions are updated throughout the day.

Analyst	Institution
Cory Kasimov	Evercore ISI
Tessa Romero	J.P. Morgan
Joseph Catanzaro	Mizuho Securities USA LLC