13F reference period
Q2 2026
Security Snapshot
Upstream Bio, Inc. - COMMON STOCK (UPB) Institutional Ownership
CUSIP: 91678A107
13F Institutional Holders and Ownership History from Q4 2024 to Q3 2026
Institutions Reporting
147
Shares (Excl. Options)
50.57M
Full value: 50,571,157 · shares · 30 Jun 2026Price
$6.92
The headline uses the Q2 2026 reference period after its reporting deadline. Available reports may still be incomplete or amended. Newer periods in the history table contain incoming reports and may be incomplete.
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- Security type / class
- Equity / COMMON STOCK
- Symbol
- UPB on Nasdaq
- All holders as of 30 Jun 2026
- Q2 2026
- Total 13F shares
- 50,571,157
- Total 13F value
- $350,077,265
- Portfolio coverage rank
- 0%
- Share change
- +5,282,041
- Value change
- +$29,894,148
- Number of holders
- 147
- Shares outstanding
- 54,984,855
- SEC-reported price per share
- $4.17
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
2 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Filing notes and source
Key facts
- UPB - Upstream Bio, Inc. - COMMON STOCK is tracked under CUSIP 91678A107.
- 147 institutions reported positions in Q2 2026.
- 6 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 138 to 147 between Q1 2026 and Q2 2026.
- SEC-reported value moved from to
$403.62M
Full value: $403,623,162 · USD · 31 Mar 2026.$350.08M
Full value: $350,077,265 · USD · 30 Jun 2026
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 147 institutions filings for Q2 2026.
Security key
91678A107
13F reference period
Q2 2026
13F holders
147
13D/G owners
6
CIK / CUSIP context first
Open Q2 2026 holders
UPB full holder history
Upstream Bio, Inc. SEC filings
Upstream Bio, Inc. company facts
Upstream Bio, Inc. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 91678A107:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
6
Security
UPB
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| NORGES BANK | 7.7% | +49% | $33,568,556 | +$10,565,033 | 4,206,586 | +46% | Norges Bank | 30 Jun 2026 |
| FMR LLC | 6.9% | -53% | $15,820,792 | -$17,275,997 | 3,793,955 | -52% | FMR LLC | 30 Oct 2026 |
| BlackRock, Inc. | 5.2% | $19,477,821 | 2,814,714 | BlackRock, Inc. | 30 Jun 2026 | |||
| Decheng Capital Global Life Sciences Fund IV, L.P. | 4.9% | -2% | $14,360,327 | 2,724,868 | 0% | Decheng Capital Global Life Sciences Fund IV, L.P. | 30 Sep 2026 | |
| HBM Healthcare Investments (Cayman) Ltd. | 4.1% | -20% | $41,290,257 | -$9,780,217 | 2,195,111 | -19% | HBM Healthcare Investments (Cayman) Ltd. | 30 Sep 2025 |
| TCG Crossover GP I, LLC | 3.9% | -26% | $39,822,919 | -$12,878,523 | 2,117,103 | -24% | TCG Crossover GP I, LLC | 30 Sep 2025 |
As of 30 Jun 2026,
147
institutional investors reported holding
shares of
Upstream Bio, Inc. - COMMON STOCK (UPB).
This represents
92%
of the company’s total
outstanding shares.
50.57M
Full value: 50,571,157 · shares · 30 Jun 202654.98M
Full value: 54,984,855 · shares · Stored outstanding share count13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
76%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| FMR LLC | 15% | 8,162,897 | +0.76% | 0% | $56,487,247 |
| ORBIMED ADVISORS LLC | 10% | 5,693,589 | 0% | 0.75% | $39,399,636 |
| NORGES BANK | 6.9% | 3,768,619 | 0% | $26,078,843 | |
| BlackRock, Inc. | 6.8% | 3,753,358 | +11% | 0% | $25,973,237 |
| Decheng Capital LLC | 5% | 2,724,868 | 0% | 2.6% | $18,856,087 |
| ENAVATE SCIENCES GP, LLC | 4.5% | 2,459,703 | 0% | 4.9% | $17,021,145 |
| VANGUARD CAPITAL MANAGEMENT LLC | 3.4% | 1,876,734 | +0.17% | 0% | $12,986,999 |
| MILLENNIUM MANAGEMENT LLC | 2.1% | 1,143,775 | +22% | 0.01% | $7,914,923 |
| D. E. Shaw & Co., Inc. | 1.9% | 1,036,044 | +26% | 0% | $7,169,425 |
| JPMORGAN CHASE & CO | 1.8% | 1,012,044 | +119% | 0% | $7,013,464 |
| Qube Research & Technologies Ltd | 1.8% | 978,500 | +58% | 0.01% | $6,771,220 |
| Parkman Healthcare Partners LLC | 1.7% | 935,247 | +19% | 0.66% | $6,471,909 |
| GEODE CAPITAL MANAGEMENT, LLC | 1.7% | 931,261 | -2% | 0% | $6,445,888 |
| SEB Asset Management AB | 1.6% | 878,473 | 0% | 0.02% | $6,079,022 |
| Woodline Partners LP | 1.5% | 831,481 | 0% | 0.02% | $5,753,849 |
| STATE STREET CORP | 1.4% | 766,323 | +8.6% | 0% | $5,302,955 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 1.3% | 712,667 | -2.1% | 0% | $4,931,656 |
| Y-Intercept (Hong Kong) Ltd | 1.3% | 693,555 | -31% | 0.09% | $4,799,401 |
| Bain Capital Life Sciences Investors, LLC | 1.1% | 600,949 | -31% | 0.25% | $4,158,567 |
| AQR CAPITAL MANAGEMENT LLC | 0.99% | 544,869 | +655% | 0% | $3,770,493 |
| MORGAN STANLEY | 0.95% | 524,632 | -5.1% | 0% | $3,630,453 |
| BNP PARIBAS FINANCIAL MARKETS | 0.93% | 511,546 | 0% | 0% | $3,539,898 |
| Walleye Capital LLC | 0.91% | 498,490 | 0.02% | $3,449,551 | |
| Trexquant Investment LP | 0.85% | 466,430 | +164% | 0.02% | $3,227,696 |
| Point72 Asset Management, L.P. | 0.82% | 453,011 | +154% | 0% | $3,134,836 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
8
Headline period
Q2 2026
Rows shown
1-8 of 8
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q3 | 3,115,974 | $16,421,194 | -$1,066,202 | $5.27 | 24 |
| 2026 Q2 | 50,571,157 | $350,077,265 | +$29,894,148 | $6.92 | 147 |
| 2026 Q1 | 44,855,500 | $403,623,162 | -$257,352,678 | $9.00 | 138 |
| 2025 Q4 | 51,176,304 | $1,389,381,175 | +$178,186,919 | $27.15 | 133 |
| 2025 Q3 | 44,461,719 | $836,327,467 | -$50,813,162 | $18.81 | 94 |
| 2025 Q2 | 48,353,677 | $530,923,062 | +$32,738,813 | $10.98 | 82 |
| 2025 Q1 | 42,073,968 | $257,482,324 | -$17,702,490 | $6.12 | 76 |
| 2024 Q4 | 42,074,592 | $690,108,943 | +$649,643,232 | $16.44 | 70 |