13F

Stock

Upstream Bio, Inc.

UPB · held by 134 managers

Reported value

$1.39B

Holders

134

+2 new · −0 exited

Holders’ est. mark

$22.3M

Price effect on 7 books still in the name

Largest holder

$204.1M

Fidelity

Notable conviction

Share of each notable manager’s 13F book.

Holder count by quarter

Who holds it

Notable only
InvestorSharesValueEst. markChange
Fidelity7.52M$204.1MHeld
ORBIMED ADVISORS LLC5.69M$154.6MHeld
BlackRock, Inc.3.34M$90.8MHeld
Decheng Capital LLC3.14M$85.3MHeld
NORGES BANK2.88M$78.3M$20.4MAdded$72.3M
ENAVATE SCIENCES GP, LLC2.46M$66.8MHeld
Vanguard2.39M$64.8MHeld
UBS Group AG1.81M$49MHeld
JANUS HENDERSON GROUP PLC1.53M$41.4MHeld
Altshuler Shaham Ltd1.34M$36.4MHeld
Bain Capital Life Sciences Investors, LLC1.33M$36.1MHeld
Omega Fund Management, LLC1.33M$36MHeld
State Street1.32M$35.8MHeld
VR ADVISER, LLC1.17M$31.7MHeld
WELLINGTON MANAGEMENT GROUP LLP894.7K$24.3MHeld
GEODE CAPITAL MANAGEMENT, LLC851.9K$23.1MHeld
Parkman Healthcare Partners LLC834.6K$22.7MHeld
Pictet Asset Management Holding SA773.1K$21MHeld
Woodline Partners LP760.3K$20.6MHeld
Integral Health Asset Management, LLC750K$20.4MHeld
TCG Crossover Management, LLC743.9K$20.2MHeld
SAMSARA BIOCAPITAL, LLC736K$20MHeld
Vestal Point Capital, LP720K$19.5MHeld
Siren, L.L.C.588.5K$16MHeld
BARCLAYS PLC524.5K$14.2M$711.5KAdded$12.6M
MILLENNIUM MANAGEMENT LLC517.3K$14MHeld
Nantahala Capital Management, LLC495K$13.4MHeld
MARSHALL WACE, LLP343.8K$9.33MHeld
GOLDMAN SACHS GROUP INC333.5K$9.05MHeld
GREAT POINT PARTNERS LLC300K$8.14MHeld
Alyeska Investment Group, L.P.298.3K$8.1MHeld
JENNISON ASSOCIATES LLC288.8K$7.84MHeld
CHARLES SCHWAB INVESTMENT MANAGEMENT INC284.9K$7.74MHeld
NORTHERN TRUST CORP236.8K$6.43MHeld
Squadron Capital Management LLC230.7K$6.26MHeld
Invesco Ltd.163.2K$4.43MHeld
Boxer Capital Management, LLC150K$4.07MNew
DEUTSCHE BANK AG\127.8K$3.47MHeld
MORGAN STANLEY122.1K$3.31M$730KAdded$1.67M
SummitTX Capital, L.P.116.7K$3.17MHeld
Schonfeld Strategic Advisors LLC115.8K$3.14MHeld
JPMORGAN CHASE & CO110.3K$2.99MHeld
AMERICAN CENTURY COMPANIES INC87.8K$2.38MHeld
BANK OF AMERICA CORP /DE/86.4K$2.35M$462.6KAdded$1.3M
Bank of New York Mellon Corp84.9K$2.3MHeld
Nuveen, LLC78.6K$2.13MHeld
ExodusPoint Capital Management, LP75.4K$2.05MHeld
Artia Global Partners LP68.7K$1.86MHeld
Exome Asset Management LLC64.8K$1.76MHeld
AMERIPRISE FINANCIAL INC56.6K$1.54MHeld
SUSQUEHANNA INTERNATIONAL GROUP, LLP55.8K$1.52MHeld
SEVEN GRAND MANAGERS, LLC50K$1.36MHeld
Y-Intercept (Hong Kong) Ltd46.6K$1.26MHeld
ALPS ADVISORS INC44.4K$1.2MHeld
RHUMBLINE ADVISERS41.5K$1.13MHeld
Rafferty Asset Management, LLC38.7K$1.05MHeld
WELLS FARGO & COMPANY/MN36.8K$999KHeld
Trexquant Investment LP31K$843KHeld
ALLIANCEBERNSTEIN L.P.31K$841.9KHeld
Icahn Capital30.5K$828.2KHeld
D. E. Shaw & Co., Inc.27.1K$735.5KHeld
Swiss National Bank26.6K$722.2KHeld
DIADEMA PARTNERS LP20.5K$556.6KHeld
MetLife Investment Management, LLC19.7K$534.3KHeld
PSP Research LLC17.6K$478.8KHeld
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.17.5K$475.3KHeld
PRELUDE CAPITAL MANAGEMENT, LLC16.6K$449.6KHeld
Renaissance Technologies16.4K$445.3KHeld
Quantinno Capital Management LP15.4K$418.5KHeld
XTX Topco Ltd15.1K$409.7KHeld
CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM14.7K$397.8KHeld
PROFUND ADVISORS LLC14.6K$395.9KHeld
Graham Capital Management, L.P.13.7K$372.3KHeld
Legal & General Group Plc13.7K$372.2KHeld
Citadel13.4K$364.4KHeld
DNB Asset Management AS12.8K$347.3KHeld
Verition Fund Management LLC12K$326.3KHeld
Mariner, LLC11.8K$321.2KHeld
Creative Planning11.7K$319KHeld
NEW YORK STATE COMMON RETIREMENT FUND11.7K$317.7KHeld
TWO SIGMA INVESTMENTS, LP10.5K$285.1KHeld
INTECH INVESTMENT MANAGEMENT LLC10.4K$282.3KHeld
MANUFACTURERS LIFE INSURANCE COMPANY, THE10.1K$275.5KHeld
Virtus Investment Advisers, LLC9.8K$266.1KHeld
STRS OHIO9.8K$266.1KHeld
VARCOV Co.9.62K$261.2KHeld
Police & Firemen's Retirement System of New Jersey9.46K$256.7KHeld
Persistent Asset Partners Ltd8.91K$241.8KNew
China Universal Asset Management Co., Ltd.8.81K$239.1KHeld
ProShare Advisors LLC8.35K$226.8KHeld
SEI INVESTMENTS CO8.09K$219.6KHeld
CITIGROUP INC6.95K$188.7KHeld
BNP PARIBAS FINANCIAL MARKETS4.98K$135.1KHeld
KLP KAPITALFORVALTNING AS2.9K$78.7KHeld
Russell Investments Group, Ltd.2.82K$76.6KHeld
Ameritas Investment Partners, Inc.2.74K$74.4KHeld
Mirae Asset Global Investments Co., Ltd.2.63K$71.3KHeld
Wellington Grp LLC2K$54.3KHeld
Sterling Capital Management LLC1.92K$52.1KHeld
Torren Management, LLC1.1K$29.8KHeld
GF FUND MANAGEMENT CO. LTD.1.06K$28.8KHeld
ROYAL BANK OF CANADA969$26KHeld
GAMMA Investing LLC900$24.4KHeld
Tower Research Capital LLC (TRC)669$18.2KHeld
Versant Capital Management, Inc558$15.2KHeld
US BANCORP \DE\546$14.8KHeld
FEDERATED HERMES, INC.482$13.1KHeld
SIMPLEX TRADING, LLC466$12.7KHeld
NISA INVESTMENT ADVISORS, LLC400$10.9KHeld
EverSource Wealth Advisors, LLC282$7.66KHeld
Global Retirement Partners, LLC273$7.41KHeld
Aster Capital Management (DIFC) Ltd271$7.36KHeld
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC242$6.57KHeld
J.Safra Asset Management Corp128$3.48KHeld
SIGNATUREFD, LLC117$3.18KHeld
PNC Financial Services Group, Inc.106$2.88KHeld
Essential Partners LLC97$2.63K$809Added$809
Allworth Financial LP68$1.85K$559Added$586
N.E.W. Advisory Services LLC60$1.63KHeld
SageView Advisory Group, LLC30$815Held
PRICE T ROWE ASSOCIATES INC /MD/19.6K$534Held
Sunbelt Securities, Inc.19$516Held
Larson Financial Group LLC14$380Held
Virtu Financial LLC12.2K$332Held
SG Americas Securities, LLC5.52K$150Held
OSAIC HOLDINGS, INC.5$136Held
CWM, LLC3.36K$91Held
Parallel Advisors, LLC2$54Held
Arax Advisory Partners2$54Held
AMALGAMATED BANK1.03K$28Held
ROTHSCHILD INVESTMENT LLC1$27Held
IFP Advisors, Inc1$27$8Cut−$11
Daiwa Securities Group Inc.180$5Held
NOMURA ASSET MANAGEMENT CO LTD0$0Held

Positions as of Q4 2025. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.