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Upstream Bio, Inc.

UPB
Exchange
Nasdaq
Industry
Pharmaceutical Preparations
SEC CIK
0002022626

In the last 90 days, Upstream Bio, Inc. insiders filed 0 open-market purchases and 5 sales; 148 institutions reported holding it in 13F filings for Q2 2026, worth $350.1M in total; no superinvestor holds it.

13F holders, Q2 2026

Institutional positions in Upstream Bio, Inc. as of Jun 30, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
148
+9 vs. Q1 2026
Shares held
50.6M
+5.69M (+12.7%) vs. Q1 2026
Total value
$350.1M
−$54.4M (−13.4%) vs. Q1 2026
New holders
37
65 more added
Sold out
28
28 more reduced

1 institution that held it in Q1 2026 haven't filed for Q2 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q1 2026: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting UPB on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ2 2026: 148 institutions
Q1 2021: 0 institutionsQ2 2021: 0 institutionsQ3 2021: 0 institutionsQ4 2021: 0 institutionsQ1 2022: 0 institutionsQ2 2022: 0 institutionsQ3 2022: 0 institutionsQ4 2022: 0 institutionsQ1 2023: 0 institutionsQ2 2023: 0 institutionsQ3 2023: 0 institutionsQ4 2023: 0 institutionsQ1 2024: 0 institutionsQ2 2024: 0 institutionsQ3 2024: 0 institutionsQ4 2024: 70 institutionsQ1 2025: 79 institutionsQ2 2025: 83 institutionsQ3 2025: 95 institutionsQ4 2025: 133 institutionsQ1 2026: 140 institutionsQ2 2026: 148 institutions
Value heldQ2 2026: $350.1M
Q1 2021: $0Q2 2021: $0Q3 2021: $0Q4 2021: $0Q1 2022: $0Q2 2022: $0Q3 2022: $0Q4 2022: $0Q1 2023: $0Q2 2023: $0Q3 2023: $0Q4 2023: $0Q1 2024: $0Q2 2024: $0Q3 2024: $0Q4 2024: $690.1MQ1 2025: $266.9MQ2 2025: $531.0MQ3 2025: $836.9MQ4 2025: $1.39BQ1 2026: $404.5MQ2 2026: $350.1M
Institutions holding UPB and their total value by quarter
QuarterHoldersValue
Q2 2026148$350.1M
Q1 2026140$404.5M
Q4 2025133$1.39B
Q3 202595$836.9M
Q2 202583$531.0M
Q1 202579$266.9M
Q4 202470$690.1M
Q3 20240$0
Q2 20240$0
Q1 20240$0
Q4 20230$0
Q3 20230$0
Q2 20230$0
Q1 20230$0
Q4 20220$0
Q3 20220$0
Q2 20220$0
Q1 20220$0
Q4 20210$0
Q3 20210$0
Q2 20210$0
Q1 20210$0

Institutions, Q2 2026

Shares, value and share of portfolio for each institution holding Upstream Bio, Inc.; share changes are against Q1 2026.

Institutions holding UPB in Q2 2026
InstitutionSharesValue% of portfolioChange in sharesAction
FMR LLC8,162,897$56.5M0.00%+61,334+0.8%Added
OrbiMed Advisors LLC5,693,589$39.4M0.75%00.0%Unchanged
Norges Bank3,768,619$26.1M0.00%+3,768,619New
BlackRock, Inc.3,753,358$26.0M0.00%+382,669+11.4%Added
Decheng Capital LLC2,724,868$18.9M2.58%00.0%Unchanged
Enavate Sciences GP, LLC2,459,703$17.0M4.93%00.0%Unchanged
Vanguard Capital Management LLC1,876,734$13.0M0.00%+3,160+0.2%Added
Millennium Management LLC1,143,775$7.91M0.01%+206,452+22.0%Added
D. E. Shaw & Co., Inc.1,036,044$7.17M0.00%+215,564+26.3%Added
JPMorgan Chase & Co1,012,044$7.01M0.00%+549,043+118.6%Added
Qube Research & Technologies Ltd978,500$6.77M0.01%+359,179+58.0%Added
Parkman Healthcare Partners LLC935,247$6.47M0.66%+148,464+18.9%Added
Geode Capital Management, LLC931,261$6.45M0.00%−19,356−2.0%Reduced
SEB Asset Management AB878,473$6.08M0.02%00.0%Unchanged
Woodline Partners LP831,481$5.75M0.02%00.0%Unchanged
State Street Corp766,323$5.30M0.00%+60,973+8.6%Added
Vanguard Portfolio Management LLC712,667$4.93M0.00%−15,044−2.1%Reduced
Y-Intercept (Hong Kong) Ltd693,555$4.80M0.09%−307,076−30.7%Reduced
Bain Capital Life Sciences Investors, LLC600,949$4.16M0.25%−266,262−30.7%Reduced
AQR Capital Management LLC544,869$3.77M0.00%+472,698+655.0%Added
Morgan Stanley524,632$3.63M0.00%−27,977−5.1%Reduced
BNP Paribas Arbitrage, SA511,546$3.54M0.00%+385,546+306.0%Added
Walleye Capital LLC498,490$3.45M0.02%+498,490New
Trexquant Investment LP466,430$3.23M0.02%+289,773+164.0%Added
Point72 Asset Management, L.P.453,011$3.13M0.00%+274,843+154.3%Added
Bank of America Corp391,762$2.71M0.00%+343,302+708.4%Added
Dimensional Fund Advisors LP381,613$2.64M0.00%+301,611+377.0%Added
Altshuler Shaham Ltd380,061$2.63M0.03%00.0%Unchanged
Arrowstreet Capital, Limited Partnership357,756$2.48M0.00%+172,669+93.3%Added
Samsara BioCapital, LLC353,717$2.45M0.20%−382,330−51.9%Reduced
Propel Bio Management, LLC350,389$2.42M1.27%+8,610+2.5%Added
Wellington Management Group LLP342,353$2.37M0.00%00.0%Unchanged
Northern Trust Corp297,346$2.06M0.00%+36,354+13.9%Added
Squarepoint Ops LLC290,904$2.01M0.00%+246,278+551.9%Added
Voleon Capital Management LP285,234$1.97M0.04%+285,234New
Charles Schwab Investment Management Inc262,456$1.82M0.00%+4,727+1.8%Added
Jacobs Levy Equity Management, Inc253,092$1.75M0.01%+253,092New
Goldman Sachs Group Inc246,917$1.71M0.00%−69,670−22.0%Reduced
XTX Topco Ltd242,346$1.68M0.02%+33,069+15.8%Added
Deutsche Bank AG241,447$1.67M0.00%+60,558+33.5%Added
Vanguard Fiduciary Trust Co239,616$1.66M0.00%+15,459+6.9%Added
UBS Group AG234,714$1.62M0.00%+3,460+1.5%Added
Schonfeld Strategic Advisors LLC225,760$1.56M0.01%+64,411+39.9%Added
Jump Financial, LLC223,223$1.54M0.01%−96,177−30.1%Reduced
Sphera Funds Management Ltd.219,700$1.52M0.22%−138,300−38.6%Reduced
Acadian Asset Management LLC175,110$1.21M0.00%+175,110New
HRT Financial LP170,590$1.18M0.00%+170,590New
Boxer Capital Management, LLC150,000$1.04M0.08%00.0%Unchanged
Renaissance Technologies LLC131,300$908.6K0.00%+69,200+111.4%Added
EntryPoint Capital, LLC129,446$895.8K0.22%+55,878+76.0%Added
Algert Global LLC118,630$820.9K0.01%+118,630New
Bank of New York Mellon Corp85,747$593.4K0.00%+4,364+5.4%Added
Nuveen, LLC84,770$586.6K0.00%+9,234+12.2%Added
American Century Companies Inc78,194$541.1K0.00%−9,430−10.8%Reduced
Man Group plc73,823$510.9K0.00%+52,669+249.0%Added
Gsa Capital Partners LLP69,348$480.0K0.03%+30,116+76.8%Added
Alliancebernstein L.P.51,680$465.1K0.00%+20,670+66.7%Added
Simplify Asset Management Inc.62,113$429.8K0.01%−15,680−20.2%Reduced
Alps Advisors Inc55,228$382.2K0.00%+11,236+25.5%Added
Quantinno Capital Management LP54,838$379.5K0.00%+5,449+11.0%Added
Virtus Investment Advisers, Inc.53,638$371.2K0.09%+43,592+433.9%Added
Invesco Ltd.53,397$369.5K0.00%+12,887+31.8%Added
Brevan Howard Capital Management LP50,369$348.6K0.00%+50,369New
Swiss National Bank48,100$332.9K0.00%00.0%Unchanged
Russell Investments Group, Ltd.47,543$329.0K0.00%+43,896+1,203.6%Added
Allspring Global Investments Holdings, LLC43,182$298.8K0.00%+43,182New
Rhumbline Advisers42,384$293.3K0.00%+1,181+2.9%Added
Two Sigma Investments, LP42,325$292.9K0.00%+42,325New
ExodusPoint Capital Management, LP41,045$284.0K0.00%−50,386−55.1%Reduced
Citigroup Inc40,339$279.1K0.00%+35,284+698.0%Added
California State Teachers Retirement System38,634$267.3K0.00%−1,027−2.6%Reduced
Stonepine Capital Management, LLC33,432$231.3K0.18%−1,568−4.5%Reduced
Mariner, LLC33,141$229.3K0.00%+5,827+21.3%Added
Wells Fargo & Company29,497$204.1K0.00%+11,095+60.3%Added
Barclays PLC29,208$202.1K0.00%+4,488+18.2%Added
Creative Planning28,483$197.1K0.00%+17,633+162.5%Added
Price T Rowe Associates Inc28,058$195.0K0.00%+1,624+6.1%Added
Quantbot Technologies LP28,178$195.0K0.01%+27,515+4,150.1%Added
Axq Capital, LP27,068$187.3K0.02%−435−1.6%Reduced
nVerses Capital, LLC24,029$166.3K0.26%+24,029New
DnB Asset Management AS23,600$163.3K0.00%+85+0.4%Added
Vanguard Asset Management, Ltd22,724$157.3K0.00%+13,474+145.7%Added
Graham Capital Management, L.P.22,508$155.8K0.00%+22,508New
Los Angeles Capital Management LLC22,385$154.9K0.00%+22,385New
Verdad Advisers, LP21,810$150.9K0.14%+21,810New
MetLife Investment Management20,852$144.3K0.00%+1,472+7.6%Added
SG Americas Securities, LLC20,338$141.0K0.00%+20,338New
SEI Investments Co20,026$138.6K0.00%+20,026New
Winton Group Ltd19,800$137.0K0.00%+19,800New
Ieq Capital, LLC19,535$135.2K0.00%+19,535New
Diadema Partners LP19,093$132.1K0.05%−2,516−11.6%Reduced
Shay Capital LLC18,000$124.6K0.01%+8,000+80.0%Added
Quadrature Capital Ltd17,988$124.5K0.00%+17,988New
Entropy Technologies, LP17,542$121.4K0.00%−5,794−24.8%Reduced
State of Wisconsin Investment Board17,065$118.1K0.00%−24,606−59.0%Reduced
Mirae Asset Global ETFs Holdings Ltd.16,217$112.2K0.00%+609+3.9%Added
Manufacturers Life Insurance Company, The15,735$108.9K0.00%+397+2.6%Added
Jane Street Group, LLC15,594$107.9K0.00%+15,594New
Mercer Global Advisors Inc13,352$92.4K0.00%+13,352New
Vanguard Global Advisers, LLC13,059$90.4K0.00%00.0%Unchanged