Upstream Bio, Inc.

UPB • XNAS

Upstream Bio, Inc. is a pharmaceutical preparations company on XNAS, led by E. Rand Sutherland, with a market cap of $1.5B. As of Q3 2025, 82% of shares are held by 94 institutional investors, with FMR LLC as the largest holder at 15.0%.

Chief Executive OfficerE. Rand Sutherland

Market Cap$1.5B

PHARMACEUTICAL PREPARATIONS

Websiteupstreambio.com

Overview

Overview of institutional ownership in UPB as of Q3 2025 with a market cap of $1.0B

All Institutions

Institutions: 94
Value Held: $836.3M
Shares Held: 44.5M
Avg Position: $8.9M
Median Position: $495.6K

Hedge Funds

Hedge Funds: 16
Value Held: $170.4M
Shares Held: 9.1M
Avg Position: $10.6M
Median Position: $1.7M

Ownership Breakdown

Institutional (non-HF)

65.67%

$665.9M

Hedge Funds

16.8%

$170.4M

Retail & Other

17.53%

$177.7M

Based on market cap of $1.0B as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in UPB as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
FMR LLC Institution	-	$152.1M 0.01% of portfolio	15.00% 8.1M shares	Q4 2024 Held for 11 months	$1.92T
ORBIMED ADVISORS LLC Hedge Fund•Sector	Sam Block Iii CFO	$107.1M 2.60% of portfolio	10.56% 5.7M shares	Q4 2024 Held for 11 months	$4.1B
Decheng Capital LLC Venture Capital	Xiangmin Nmn Cui Managing Partner	$61.8M 10.78% of portfolio	6.09% 3.3M shares	Q4 2024 Held for 11 months	$573.2M
B BlackRock, Inc. Institution	-	$49.0M 0.00% of portfolio	4.83% 2.6M shares	Q4 2024 Held for 11 months	$5.67T
E Enavate Sciences GP, LLC Institution	-	$46.3M 14.13% of portfolio	4.56% 2.5M shares	Q4 2024 Held for 11 months	$327.5M
VANGUARD GROUP INC Institution	Salim Ramji CEO	$45.9M 0.00% of portfolio	4.53% 2.4M shares	Q4 2024 Held for 11 months	$6.69T
B Bain Capital Life Sciences Investors, LLC Institution	-	$45.9M 3.05% of portfolio	4.53% 2.4M shares	Q4 2024 Held for 11 months	$1.5B
TCG Crossover Management, LLC Venture Capital	Chen Ming Yu Managing Partner	$39.8M 1.99% of portfolio	3.93% 2.1M shares	Q4 2024 Held for 11 months	$2.0B
A Altshuler Shaham Ltd Institution	-	$26.7M 0.44% of portfolio	2.63% 1.4M shares	Q1 2025 Held for 8 months	$6.0B
Omega Fund Management Inc. Venture Capital	Alexandra Rankel Pearsall CFO	$25.5M 11.47% of portfolio	2.52% 1.4M shares	Q4 2024 Held for 11 months	$222.4M

Net Capital Flow

Institutional buying and selling activity for UPB in Q3 2025

Traded: −$40.1M
Buyers: 60
Sellers: 31
Total Bought: +$80.0M
Total Sold: −$120.1M
Avg Position: $8.1M

Biggest Buyers

Institution	Net Bought	Current Position
STATE STREET CORP Institution	+$11.9M +633.2K shares	$21.0M 1.1M shares
Marshall Wace LLP Institution	+$10.9M +577.5K shares	$16.3M 868.0K shares
Integral Health Asset Management, LLC Hedge Fund•Sector	+$10.8M +575.0K shares	$10.8M 575.0K shares
B BlackRock, Inc. Institution	+$9.5M +507.2K shares	$49.0M 2.6M shares
VANGUARD GROUP INC Institution	+$5.1M +271.7K shares	$45.9M 2.4M shares
GOLDMAN SACHS GROUP INC Institution	+$4.2M +223.2K shares	$4.2M 223.2K shares
GEODE CAPITAL MANAGEMENT LLC ETF Provider	+$3.2M +170.5K shares	$15.4M 817.1K shares
Ikarian Capital, LLC Hedge Fund•Event Driven	+$3.0M +161.1K shares	$3.0M 161.1K shares
FMR LLC Institution	+$2.8M +149.5K shares	$152.1M 8.1M shares
Parkman Healthcare Partners LLC Hedge Fund•Long/Short	+$2.4M +128.0K shares	$15.9M 843.5K shares

Biggest Sellers

Institution	Net Sold	Current Position
A Altshuler Shaham Ltd Institution	−$37.2M −2.0M shares	$26.7M 1.4M shares
VR Adviser, LLC Venture Capital	−$21.2M −1.1M shares	$22.0M 1.2M shares
Deep Track Capital, LP Hedge Fund•Long/Short	−$15.8M −1.4M shares	Sold Off 0 shares
TCG Crossover Management, LLC Venture Capital	−$12.9M −684.7K shares	$39.8M 2.1M shares
Omega Fund Management Inc. Venture Capital	−$12.8M −680.0K shares	$25.5M 1.4M shares
Samsara BioCapital, LLC Venture Capital	−$9.0M −481.1K shares	$18.1M 962.2K shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	−$3.3M −175.5K shares	$3.6M 190.2K shares
L Lynx1 Capital Management LP Hedge Fund•Sector	−$2.4M −219.2K shares	Sold Off 0 shares
WELLINGTON MANAGEMENT CO LLP Long Only Manager	−$1.9M −99.9K shares	$21.2M 1.1M shares
V Velan Capital Investment Management LP Institution	−$1.2M −107.0K shares	Sold Off 0 shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited UPB in Q3 2025

New Positions: 17
New Value: $20.2M
Exited Positions: 9
Exited Value: $20.8M

New Positions

Institution	Position Value
Integral Health Asset Management, LLC Hedge Fund•Sector	$10.8M 575.0K shares
Ikarian Capital, LLC Hedge Fund•Event Driven	$3.0M 161.1K shares
SummitTX Capital, L.P. Hedge Fund•Multi-Strategy	$2.1M 112.4K shares
BOOTHBAY FUND MANAGEMENT, LLC Fund of Funds	$1.2M 61.3K shares
Exome Asset Management LLC Hedge Fund•Sector	$977.4K 52.0K shares
R Rafferty Asset Management, LLC Institution	$649.3K 34.5K shares
N NOMURA HOLDINGS INC Institution	$532.1K 28.3K shares
Caption Management, LLC Hedge Fund•Long/Short	$342.3K 18.2K shares
SPRINGBOK CAPITAL MANAGEMENT, LLC Fund of Funds	$296.0K 15.7K shares
Mariner Wealth Advisors, LLC RIA/Wealth	$205.7K 10.9K shares

Exited Positions

Institution	Previous Position
Deep Track Capital, LP Hedge Fund•Long/Short	$15.8M 1.4M shares
L Lynx1 Capital Management LP Hedge Fund•Sector	$2.4M 219.2K shares
V Velan Capital Investment Management LP Institution	$1.2M 107.0K shares
A Alyeska Investment Group, L.P. Hedge Fund•Multi-Strategy	$933.3K 85.0K shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$464.0K 42.3K shares
S STRS OHIO Institution	$19.8K 1.8K shares
Caitong International Asset Management Co., Ltd RIA/Wealth	$2.5K 224.0 shares
True Wealth Design, LLC RIA/Wealth	$341.0 31.0 shares
A Advisor Group Holdings, Inc. Institution	$257.0 42.0 shares

Options Activity

Institutions with the largest Call and Put options positions in UPB as of Q3 2025

Call Positions: 6
Call Value: $7.7M
Put Positions: 1
Put Value: $355.5K

Call Positions

Institution	Position Value
DIADEMA PARTNERS LP Hedge Fund•Long/Short	$3.8M 2.0K contracts
Caption Management, LLC Hedge Fund•Long/Short	$1.3M 700.0 contracts
N NOMURA HOLDINGS INC Institution	$1.3M 700.0 contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$532.3K 283.0 contracts
J JANE STREET GROUP, LLC Institution	$385.6K 205.0 contracts
S SIG BROKERAGE, LP Institution	$376.2K 200.0 contracts

Put Positions

Institution	Position Value
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$355.5K 189.0 contracts

Most Committed Institutions

Institutions with UPB as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
E Enavate Sciences GP, LLC Institution	-	14.13% $46.3M	4.56% 2.5M shares	Q4 2024 Held for 11 months	$327.5M
Omega Fund Management Inc. Venture Capital	Alexandra Rankel Pearsall CFO	11.47% $25.5M	2.52% 1.4M shares	Q4 2024 Held for 11 months	$222.4M
Decheng Capital LLC Venture Capital	Xiangmin Nmn Cui Managing Partner	10.78% $61.8M	6.09% 3.3M shares	Q4 2024 Held for 11 months	$573.2M
B Bain Capital Life Sciences Investors, LLC Institution	-	3.05% $45.9M	4.53% 2.4M shares	Q4 2024 Held for 11 months	$1.5B
ORBIMED ADVISORS LLC Hedge Fund•Sector	Sam Block Iii CFO	2.60% $107.1M	10.56% 5.7M shares	Q4 2024 Held for 11 months	$4.1B
G GREAT POINT PARTNERS LLC Private Equity	Jeffrey Robert Jay Managing Partner	2.49% $5.6M	0.56% 300.0K shares	Q4 2024 Held for 11 months	$226.8M
Samsara BioCapital, LLC Venture Capital	Miran Nasruddin Ahmad CFO	2.36% $18.1M	1.78% 962.2K shares	Q4 2024 Held for 11 months	$765.9M
TCG Crossover Management, LLC Venture Capital	Chen Ming Yu Managing Partner	1.99% $39.8M	3.93% 2.1M shares	Q4 2024 Held for 11 months	$2.0B
Parkman Healthcare Partners LLC Hedge Fund•Long/Short	Gregory Arthur Martinez CIO	1.74% $15.9M	1.56% 843.5K shares	Q1 2025 Held for 8 months	$910.1M
VR Adviser, LLC Venture Capital	Jessica Tong Baron CFO	1.24% $22.0M	2.17% 1.2M shares	Q4 2024 Held for 11 months	$1.8B

Hedge Fund Spotlight

Discover hedge funds investing in UPB

Woodline Partners LP

Hedge Fund • Long/Short

Portfolio ManagerKarl Heinz Kroeker

Portfolio Value: $21.3B
Positions: 868
Last Reported: Q3 2025

Sector Allocation

Position in Upstream Bio, Inc.

Market Value: $11.3M
Shares Held: 602.3K
Portfolio Weight: 0.05%
Owned Since: 2024-Q4

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