UPB · Upstream Bio, Inc. · Holdings
The latest filing states the doubt was alleviated.
“The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company's ability to continue as a going concern within one year from the issuance of these condensed consolidated financial statements. The Company expects its cash, cash equivalents and short-term investments will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next twelve months from the date of issuance of these condensed consolidated financial statements.”View the 10-Q filed May 13, 2026
Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.
Institutional Ownership Trend
Holder Concentration
Across 150 13F filersWho Holds UPB
Last 8 quarters through Sep 30, 2026 (filing window open)Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.
Jun 30, 2026, the newest closed quarter: 148 filers, like-for-like change +4.3%; actively managed books +6.0%; index-like books -2.3%.
| Holder type | Share | Filers | Change |
|---|---|---|---|
| Registered adviser | 36.0% | 67 | +15.2% |
| Exempt adviser | 3.8% | 5 | -5.0% |
| Adviser | 0.2% | 3 | -91.7% |
| Bank | 5.7% | 13 | +57.1% |
| Benefit plan | 0.1% | 4 | -20.6% |
| Non-US | 9.0% | 7 | +148.3% |
| Holding company | 25.9% | 8 | +3.2% |
| Broker-dealer | 0.0% | 0 | — |
| Insurer | 0.0% | 0 | — |
| Unknown | 19.2% | 41 | -12.0% |
| Style | Share | Filers | Change |
|---|---|---|---|
| Index-like | 25.3% | 23 | -2.3% |
| Systematic-like | 12.3% | 19 | +17.6% |
| Concentrated | 13.4% | 16 | -11.5% |
| Diversified active | 49.0% | 90 | +9.2% |
| Not measured | 0.0% | 0 | — |
| Unknown | 0.0% | 0 | — |
| Turnover | Share | Filers | Change |
|---|---|---|---|
| Low turnover | 46.7% | 69 | +2.7% |
| Medium turnover | 22.9% | 33 | -2.7% |
| High turnover | 15.4% | 34 | +24.8% |
| Unknown | 15.0% | 12 | +1.6% |
| Not measured | 0.0% | 0 | — |
| Holding horizon | Share | Filers | Change |
|---|---|---|---|
| Short horizon | 10.1% | 22 | -3.3% |
| Medium horizon | 21.4% | 26 | -1.6% |
| Long horizon | 45.7% | 82 | +12.2% |
| Unknown | 22.9% | 18 | +1.4% |
| Not measured | 0.0% | 0 | — |
| 13F book size | Share | Filers | Change |
|---|---|---|---|
| Under $1B | 13.9% | 21 | -1.1% |
| $1B to $10B | 17.5% | 30 | -10.8% |
| $10B to $100B | 12.0% | 45 | +22.4% |
| $100B or more | 56.6% | 52 | +8.5% |
| Not measured | 0.0% | 0 | — |
| Client base | Share | Filers | Change |
|---|---|---|---|
| Individuals and high net worth | 0.3% | 17 | +13.3% |
| Pooled investment vehicles | 24.0% | 27 | +8.5% |
| Registered funds and BDCs | 8.6% | 9 | +7.1% |
| Pension and profit sharing plans | 0.0% | 1 | -78.1% |
| Insurance companies | 0.0% | 2 | +6.7% |
| Governments and sovereign funds | 1.2% | 3 | +188.0% |
| Other investment advisers | 0.0% | 1 | +62.8% |
| Diversified | 1.7% | 6 | +566.2% |
| Other | 0.0% | 0 | — |
| Unknown | 64.0% | 82 | -1.7% |
| Private funds | Share | Filers | Change |
|---|---|---|---|
| Hedge funds | 17.8% | 33 | +32.9% |
| Private equity funds | 0.2% | 4 | -4.6% |
| Venture capital funds | 1.4% | 3 | -34.7% |
| Real estate funds | 0.0% | 2 | +334.7% |
| Securitized asset funds | 0.0% | 1 | 0.0% |
| Other private funds | 12.4% | 6 | +7.2% |
| Mixed private funds | 0.1% | 1 | -9.7% |
| Private funds, type not stated | 0.2% | 3 | +7.5% |
| No private funds | 7.8% | 19 | +0.5% |
| Unknown | 60.1% | 76 | -1.4% |
| Location | Share | Filers | Change |
|---|---|---|---|
| United States | 84.0% | 115 | +8.0% |
| Outside the US | 16.0% | 33 | -22.0% |
The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.
How the mix is measured
Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.
Excluded 2 holders with no observed 2026-03-31 13F and 1 holder with no observed 2026-06-30 13F.
Conviction and Crowding
148 13F filers, quarter ended Jun 30, 2026Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.
Managers in the top fifth by current three-year FundScore alpha were net sellers of $21,081 (0 buying, 1 selling).
Estimated Holder Cost Basis
Quarter ended Jun 30, 2026, on that quarter's share basisEstimated, never filed: each 13F buy is costed at its quarter's average traded price and each sale keeps the average cost, so this is what holders paid on average if they traded evenly through each quarter.
Estimated cost covers 79.5% of the 13F shares; positions already held when a filer's 13F history starts, or bought in a quarter without a trusted average price, have no estimate.
Shared Holders
Companies UPB's active holders also own, quarter ended Jun 30, 2026| # | Company | Shared holders |
|---|---|---|
| 1 | HELP Helus Pharma Inc. | 5 |
| 2 | XLO Xilio Therapeutics, Inc. | 3 |
| 3 | PALI Palisade Bio, Inc. | 5 |
| 4 | CRVS Corvus Pharmaceuticals, Inc. | 5 |
| 5 | OVID Ovid Therapeutics Inc. | 4 |
| 6 | PHAT Phathom Pharmaceuticals, Inc. | 4 |
| 7 | CABA Cabaletta Bio, Inc. | 3 |
| 8 | KYTX Kyverna Therapeutics, Inc. | 3 |
| 9 | FBRX Forte Biosciences, Inc. | 3 |
| 10 | SPRB Spruce Biosciences, Inc. | 3 |
Shareholder Targets
13F filers that own its peers but not UPB, quarter ended Jun 30, 2026Found through its holder-overlap peers: HELP, XLO, PALI, CRVS, OVID, PHAT, CABA, KYTX, FBRX, SPRB, EYPT, BIOA, IVA, STTK, CRBP, MLYS, URGN, ARTV, ZNTL, ABEO. 527 filers in all.
| # | Filer | In peers | Largest peers |
|---|---|---|---|
| 1 | RA CAPITAL MANAGEMENT, L.P. Registered adviser, Concentrated | $472,552,219 6 held | MLYS, ARTV, BIOA |
| 2 | ADAGE CAPITAL PARTNERS GP, L.L.C. Registered adviser, Diversified active | $243,341,176 12 held | EYPT, STTK, CABA |
| 3 | Catalys Pacific, LLC Exempt adviser, Unknown | $229,453,864 2 held | MLYS, PHAT |
| 4 | Jupiter Topco LLC Unknown, Diversified active | $215,922,692 9 held | OVID, EYPT, BIOA |
| 5 | Cormorant Asset Management, LP Registered adviser, Diversified active | $196,239,555 4 held | EYPT, BIOA, CRBP |
| 6 | FRANKLIN RESOURCES INC Adviser, Diversified active | $191,678,575 10 held | EYPT, MLYS, PHAT |
| 7 | RTW INVESTMENTS, LP Registered adviser, Diversified active | $167,215,336 1 held | URGN |
| 8 | Frazier Life Sciences Management, L.P. Registered adviser, Concentrated | $165,334,002 3 held | PHAT, STTK, XLO |
| 9 | T. Rowe Price Investment Management, Inc. Adviser, Diversified active | $151,907,237 2 held | STTK, CABA |
| 10 | FEDERATED HERMES, INC. Adviser, Diversified active | $149,605,332 9 held | EYPT, FBRX, OVID |
Fund Ownership of UPB by Fund Type
Registered funds' Form N-PORT reports for the quarter ended Jun 30, 2026Index funds and index ETFs hold 9.38% of shares outstanding.
| Fund type | Of shares outstanding | Shares |
|---|---|---|
| Index funds | 2.13% | 1,164,222 |
| Index ETFs | 7.26% | 3,975,782 |
| Active ETFs | 0.66% | 363,584 |
| Active funds | 16.57% | 9,073,716 |
| Unclassified | 0.14% | 77,747 |
| All registered funds | 26.76% | 14,655,051 |
How fund types are measured
Each fund series counts once, with its latest Form N-PORT report dated inside the quarter; only long share positions count, restated to today's split basis. The fund type is the series' latest Form N-CEN answer on or before the quarter end (the index-fund box and the exchange-traded flag), never its name. Unclassified funds have no usable N-CEN; unit investment trusts are among them, so index ownership is a floor. Funds sit inside their advisers' 13F reports, so these shares overlap the 13F figures and are never added to them.
| Holder | Value (USD) | % of 13F | Shares | Type | Filed | Open |
|---|---|---|---|---|---|---|
| Mega FMR LLC Holding company | $56,487,246 | 16.20% | 8,162,897 | Shares | 2026-08-13 | |
| Mid ORBIMED ADVISORS LLC Registered adviser | $39,399,635 | 11.30% | 5,693,589 | Shares | 2026-08-14 | |
| Mega NORGES BANK Non-US | $26,078,843 | 7.48% | 3,768,619 | Shares | 2026-08-12 | |
| Mega BlackRock, Inc. Holding company | $25,973,232 | 7.45% | 3,753,358 | Shares | 2026-08-07 | |
| Small Decheng Capital LLC | $18,856,086 | 5.41% | 2,724,868 | Shares | 2026-08-14 | |
| Small ENAVATE SCIENCES GP, LLC | $17,021,144 | 4.88% | 2,459,703 | Shares | 2026-08-14 | |
| Mega VANGUARD CAPITAL MANAGEMENT LLC Registered adviser | $12,986,999 | 3.72% | 1,876,734 | Shares | 2026-08-13 | |
| Mega MILLENNIUM MANAGEMENT LLC Registered adviser | $7,914,923 | 2.27% | 1,143,775 | Shares | 2026-08-14 | |
| Mega D. E. Shaw & Co., Inc. | $7,169,423 | 2.06% | 1,036,044 | Shares | 2026-08-14 | |
| Mega JPMORGAN CHASE & CO Bank | $7,003,343 | 2.01% | 1,012,044 | Shares | 2026-08-12 | |
| Mega Qube Research & Technologies Ltd Exempt adviser | $6,771,220 | 1.94% | 978,500 | Shares | 2026-08-14 | |
| Small Parkman Healthcare Partners LLC Registered adviser | $6,471,909 | 1.86% | 935,247 | Shares | 2026-08-14 | |
| Mega GEODE CAPITAL MANAGEMENT, LLC Registered adviser | $6,444,325 | 1.85% | 931,261 | Shares | 2026-08-12 | |
| Large SEB Asset Management AB | $6,079,033 | 1.74% | 878,473 | Shares | 2026-08-04 | |
| Large Woodline Partners LP Registered adviser | $5,753,848 | 1.65% | 831,481 | Shares | 2026-08-14 | |
| Mega STATE STREET CORP Bank | $5,302,955 | 1.52% | 766,323 | Shares | 2026-09-22 | |
| Mega VANGUARD PORTFOLIO MANAGEMENT LLC Registered adviser | $4,931,655 | 1.41% | 712,667 | Shares | 2026-08-13 | |
| Mid Bain Capital Life Sciences Investors, LLC | $4,158,567 | 1.19% | 600,949 | Shares | 2026-08-14 | |
| Mega AQR CAPITAL MANAGEMENT LLC Registered adviser | $3,770,491 | 1.08% | 544,869 | Shares | 2026-08-14 | |
| Mega MORGAN STANLEY Holding company | $3,630,451 | 1.04% | 524,632 | Shares | 2026-08-13 | |
| Mega BNP PARIBAS ARBITRAGE, SA Non-US | $3,539,898 | 1.02% | 511,546 | Shares | 2026-08-13 | |
| Large Walleye Capital LLC Registered adviser | $3,449,550 | 0.99% | 498,490 | Shares | 2026-08-03 | |
| Mid Y-Intercept (Hong Kong) Ltd Exempt adviser | $3,386,364 | 0.97% | 642,574 | Shares | 2026-10-16 | |
| Large Trexquant Investment LP Registered adviser | $3,227,695 | 0.93% | 466,430 | Shares | 2026-08-14 | |
| Large Point72 Asset Management, L.P. Registered adviser | $3,134,836 | 0.90% | 453,011 | Shares | 2026-08-14 | |
| Mega BANK OF AMERICA CORP /DE/ Bank | $2,710,993 | 0.78% | 391,762 | Shares | 2026-08-14 | |
| Mega DIMENSIONAL FUND ADVISORS LP Registered adviser | $2,640,761 | 0.76% | 381,613 | Shares | 2026-08-11 | |
| Mid Altshuler Shaham Ltd | $2,630,022 | 0.75% | 380,061 | Shares | 2026-08-12 | |
| Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP Registered adviser | $2,475,671 | 0.71% | 357,756 | Shares | 2026-08-13 | |
| Mid SAMSARA BIOCAPITAL, LLC Registered adviser | $2,447,721 | 0.70% | 353,717 | Shares | 2026-08-14 | |
| Small Propel Bio Management, LLC Registered adviser | $2,424,691 | 0.70% | 350,389 | Shares | 2026-08-13 | |
| Mega WELLINGTON MANAGEMENT GROUP LLP Holding company | $2,369,082 | 0.68% | 342,353 | Shares | 2026-08-14 | |
| Mega NORTHERN TRUST CORP Bank | $2,057,632 | 0.59% | 297,346 | Shares | 2026-08-13 | |
| Large Squarepoint Ops LLC Registered adviser | $2,013,055 | 0.58% | 290,904 | Shares | 2026-08-14 | |
| Mid Voleon Capital Management LP Registered adviser | $1,973,819 | 0.57% | 285,234 | Shares | 2026-08-14 | |
| Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC Registered adviser | $1,816,195 | 0.52% | 262,456 | Shares | 2026-08-14 | |
| Large JACOBS LEVY EQUITY MANAGEMENT, INC Registered adviser | $1,751,396 | 0.50% | 253,092 | Shares | 2026-08-14 | |
| Mega GOLDMAN SACHS GROUP INC Holding company | $1,708,665 | 0.49% | 246,917 | Shares | 2026-08-14 | |
| Mid XTX Topco Ltd | $1,677,034 | 0.48% | 242,346 | Shares | 2026-08-14 | |
| Mega DEUTSCHE BANK AG\ Non-US | $1,670,812 | 0.48% | 241,447 | Shares | 2026-08-07 | |
| Mega VANGUARD FIDUCIARY TRUST CO | $1,658,142 | 0.48% | 239,616 | Shares | 2026-08-13 | |
| Mega UBS Group AG Bank | $1,624,220 | 0.47% | 234,714 | Shares | 2026-08-13 | |
| Large Schonfeld Strategic Advisors LLC Registered adviser | $1,562,259 | 0.45% | 225,760 | Shares | 2026-08-14 | |
| Large Jump Financial, LLC | $1,544,702 | 0.44% | 223,223 | Shares | 2026-08-13 | |
| Small SPHERA FUNDS MANAGEMENT LTD. Exempt adviser | $1,520,324 | 0.44% | 219,700 | Shares | 2026-08-14 | |
| Large ACADIAN ASSET MANAGEMENT LLC | $1,211,761 | 0.35% | 175,110 | Shares | 2026-08-13 | |
| Large HRT FINANCIAL LP | $1,180,482 | 0.34% | 170,590 | Shares | 2026-08-14 | |
| Mid Boxer Capital Management, LLC Registered adviser | $1,038,000 | 0.30% | 150,000 | Shares | 2026-08-14 | |
| Large RENAISSANCE TECHNOLOGIES LLC Registered adviser | $908,596 | 0.26% | 131,300 | Shares | 2026-08-13 | |
| Small EntryPoint Capital, LLC Registered adviser | $895,766 | 0.26% | 129,446 | Shares | 2026-08-13 | |
| Mid ALGERT GLOBAL LLC Registered adviser | $820,919 | 0.24% | 118,630 | Shares | 2026-08-13 | |
| Mega Bank of New York Mellon Corp Bank | $593,368 | 0.17% | 85,747 | Shares | 2026-08-06 | |
| Mega Nuveen, LLC | $586,608 | 0.17% | 84,770 | Shares | 2026-08-11 | |
| Mega AMERICAN CENTURY COMPANIES INC | $541,102 | 0.16% | 78,194 | Shares | 2026-08-12 | |
| Large Man Group plc | $510,855 | 0.15% | 73,823 | Shares | 2026-08-14 | |
| Mid GSA CAPITAL PARTNERS LLP Registered adviser | $479,888 | 0.14% | 69,348 | Shares | 2026-08-06 | |
| Mid Simplify Asset Management Inc. Registered adviser | $429,821 | 0.12% | 62,113 | Shares | 2026-07-16 | |
| Large ALPS ADVISORS INC Registered adviser | $382,177 | 0.11% | 55,228 | Shares | 2026-07-29 | |
| Large Quantinno Capital Management LP Registered adviser | $379,478 | 0.11% | 54,838 | Shares | 2026-08-13 | |
| Small Virtus Investment Advisers, LLC Registered adviser | $371,174 | 0.11% | 53,638 | Shares | 2026-08-11 | |
| Mega Invesco Ltd. Adviser | $369,505 | 0.11% | 53,397 | Shares | 2026-08-14 | |
| Mega ALLIANCEBERNSTEIN L.P. Registered adviser | $357,625 | 0.10% | 51,680 | Shares | 2026-08-14 | |
| Large Brevan Howard Capital Management LP Exempt adviser | $348,553 | 0.10% | 50,369 | Shares | 2026-08-14 | |
| Mega Swiss National Bank | $332,852 | 0.10% | 48,100 | Shares | 2026-08-11 | |
| Mega Russell Investments Group, Ltd. | $328,996 | 0.09% | 47,543 | Shares | 2026-08-06 | |
| Large Allspring Global Investments Holdings, LLC Holding company | $298,819 | 0.09% | 43,182 | Shares | 2026-08-13 | |
| Mega RHUMBLINE ADVISERS Registered adviser | $293,297 | 0.08% | 42,384 | Shares | 2026-08-12 | |
| Mega TWO SIGMA INVESTMENTS, LP Registered adviser | $292,889 | 0.08% | 42,325 | Shares | 2026-08-14 | |
| Large ExodusPoint Capital Management, LP Registered adviser | $284,031 | 0.08% | 41,045 | Shares | 2026-08-14 | |
| Mega CITIGROUP INC Bank | $279,145 | 0.08% | 40,339 | Shares | 2026-08-03 | |
| Mega CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM Benefit plan | $267,347 | 0.08% | 38,634 | Shares | 2026-08-24 | |
| Small Stonepine Capital Management, LLC Registered adviser | $231,349 | 0.07% | 33,432 | Shares | 2026-08-17 | |
| Large Mariner, LLC Registered adviser | $229,335 | 0.07% | 33,141 | Shares | 2026-08-13 | |
| Mega WELLS FARGO & COMPANY/MN Bank | $204,119 | 0.06% | 29,497 | Shares | 2026-08-14 | |
| Mega BARCLAYS PLC Bank | $202,118 | 0.06% | 29,208 | Shares | 2026-08-14 | |
| Mega Creative Planning Registered adviser | $197,101 | 0.06% | 28,483 | Shares | 2026-08-13 | |
| Mid Quantbot Technologies LP Registered adviser | $194,991 | 0.06% | 28,178 | Shares | 2026-08-12 | |
| Mega PRICE T ROWE ASSOCIATES INC /MD/ Registered adviser | $194,161 | 0.06% | 28,058 | Shares | 2026-08-14 | |
| Small AXQ CAPITAL, LP Registered adviser | $187,310 | 0.05% | 27,068 | Shares | 2026-08-06 | |
| Micro nVerses Capital, LLC Registered adviser | $166,280 | 0.05% | 24,029 | Shares | 2026-08-04 | |
| Large DNB Asset Management AS Adviser | $163,312 | 0.05% | 23,600 | Shares | 2026-08-11 | |
| Mega VANGUARD ASSET MANAGEMENT, Ltd | $157,250 | 0.05% | 22,724 | Shares | 2026-08-13 | |
| Mid Graham Capital Management, L.P. Registered adviser | $155,755 | 0.04% | 22,508 | Shares | 2026-08-14 | |
| Large LOS ANGELES CAPITAL MANAGEMENT LLC Registered adviser | $154,904 | 0.04% | 22,385 | Shares | 2026-08-13 | |
| Small Verdad Advisers, LP | $150,925 | 0.04% | 21,810 | Shares | 2026-08-14 | |
| Large MetLife Investment Management, LLC Registered adviser | $144,295 | 0.04% | 20,852 | Shares | 2026-08-14 | |
| Mega SG Americas Securities, LLC Non-US | $140,738 | 0.04% | 20,338 | Shares | 2026-08-07 | |
| Mega SEI INVESTMENTS CO Holding company | $138,579 | 0.04% | 20,026 | Shares | 2026-08-14 | |
| Mid WINTON GROUP Ltd | $137,016 | 0.04% | 19,800 | Shares | 2026-08-07 | |
| Large IEQ CAPITAL, LLC Registered adviser | $135,182 | 0.04% | 19,535 | Shares | 2026-08-11 | |
| Small DIADEMA PARTNERS LP Registered adviser | $132,123 | 0.04% | 19,093 | Shares | 2026-08-14 | |
| Mid Shay Capital LLC | $124,560 | 0.04% | 18,000 | Shares | 2026-08-14 | |
| Large Quadrature Capital Ltd | $124,476 | 0.04% | 17,988 | Shares | 2026-08-07 | |
| Mid Entropy Technologies, LP Registered adviser | $121,390 | 0.03% | 17,542 | Shares | 2026-08-13 | |
| Large STATE OF WISCONSIN INVESTMENT BOARD Benefit plan | $118,089 | 0.03% | 17,065 | Shares | 2026-08-14 | |
| Large MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | $112,221 | 0.03% | 16,217 | Shares | 2026-08-14 | |
| Mega MANUFACTURERS LIFE INSURANCE COMPANY, THE Non-US | $108,886 | 0.03% | 15,735 | Shares | 2026-09-09 | |
| Mega JANE STREET GROUP, LLC | $107,910 | 0.03% | 15,594 | Shares | 2026-08-14 | |
| Mega CITADEL ADVISORS LLC Registered adviser | $103,800 | 0.03% | 15,000 | Call | 2026-09-02 | |
| Large MERCER GLOBAL ADVISORS INC /ADV Registered adviser | $92,395 | 0.03% | 13,352 | Shares | 2026-08-19 |
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