Security Snapshot

Upstream Bio, Inc. - Common Stock (UPB) Institutional Ownership

CUSIP: 91678A107

13F Institutional Holders and Ownership History from Q4 2024 to Q2 2026

Latest Period

Q2 2026

Institutions Reporting

148

Shares (Excl. Options)

50,573,636

Price

$6.92

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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
50,573,636
Latest holder snapshot 5 signals
Total 13F value
$350,094,419
Portfolio coverage rank
0%
Share change
+5,284,520
Value change
+$29,911,302
Number of holders
148
Issuer context Names, identifiers, and filing context for this profile. 2 identity fields
Shares outstanding
54,419,669
SEC-reported price per share
$6.42
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors

Key facts

  • UPB - Upstream Bio, Inc. - Common Stock is tracked under CUSIP 91678A107.
  • 148 institutions reported positions in Q2 2026.
  • 6 significant owners is listed from Schedule 13D/13G reporting.

Change

  • Holder count moved from 138 to 148 between Q1 2026 and Q2 2026.
  • SEC-reported value moved from $403,623,162 to $350,094,419.

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

Latest holder context comes from 148 institutions filings for Q2 2026.

Open SEC evidence

Security key

91678A107

Latest holder period

Q2 2026

13F holders

148

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

Latest 13F filings Latest 13D/G filings All securities

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
FMR LLC 15% +11% $93,972,663 +$9,006,605 7,936,880 +11% FMR LLC 30 Jun 2025
NORGES BANK 7.7% +49% $33,568,556 +$10,565,033 4,206,586 +46% Norges Bank 30 Jun 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. 5% -18% $25,886,246 -$5,324,038 2,724,868 -17% Decheng Capital Global Life Sciences Fund IV, L.P. 31 Mar 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, 148 institutional investors reported holding 50,573,636 shares of Upstream Bio, Inc. - Common Stock (UPB). This represents 93% of the company’s total 54,419,669 outstanding shares.

13F concentration

Top 25 institutional shareholders

Largest 13F positions for this security by reported shares and value.

Top holder share
77%
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. 6.9% 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 1.9% 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 1% 544,869 +655% 0% $3,770,493
MORGAN STANLEY 0.96% 524,632 -5.1% 0% $3,630,453
BNP PARIBAS FINANCIAL MARKETS 0.94% 511,546 0% 0% $3,539,898
Walleye Capital LLC 0.92% 498,490 0.02% $3,449,551
Trexquant Investment LP 0.86% 466,430 +164% 0.02% $3,227,696
Point72 Asset Management, L.P. 0.83% 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
7
Latest
Q2 2026
Rows shown
1-7 of 7
Period 13F Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q2 50,573,636 $350,094,419 +$29,911,302 $6.92 148
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
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