Security key
91678A107
- Security type / class
- Equity / COMMON STOCK
- Total 13F shares
- 51,176,304
- Total 13F value
- $1,389,381,175
- Share change
- +6,455,037
- Put/Call ratio
- 50%
- SEC-reported price per share
- $27.15
- Number of holders
- 133
- Value change
- +$178,186,919
- Number of buys
- 83
- Number of sells
- 40
- Shares outstanding
- 54,984,855
Holder snapshot
7 signals
Open additional details 1 more signal available
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q4 2025
Institutions
133
Top holders
10
UPB full security history
Ownership snapshot
Full 13F holder table
Newer quarter: Q3 2026
Upstream Bio, Inc. SEC filings
Upstream Bio, Inc. company facts
Broader feeds
Reporting periods
Holder history for CUSIP 91678A107
Recent filing periods:
Ownership snapshot
Top reported holders of UPB - Upstream Bio, Inc. - COMMON STOCK (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
HBM Healthcare Investment...
Disclosed value leader
FMR LLC
Comparable rows
2/15
Latest evidence
30 Sep 2025
13D/G
13F
3/4/5
Lead comparable stake: 4.1%
13 rows are not safely comparable across share classes.
13D/G row: HBM Healthcare Investments (Cayman) Ltd.
Showing 1-6 of 15 holder rows.
Quick read
HBM Healthcare Investments (Cayman) Ltd. leads the comparable SEC ownership view at 4.1%.
2 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens HBM Healthcare Investments (Cayman) Ltd.'s linked filing trail.
Comparable ownership
Top 2
HBM Healthcare Investments (Cayma...
4.1%
TCG Crossover GP I, LLC
3.9%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| HBM Healthcare Investments (Cayman) Ltd. |
13D/G
|
4.1%
Reported 13D/G
· 30 Sep 2025
|
$41,290,257
2,195,111 shares
|
-$9,780,217 | 30 Sep 2025 |
| TCG Crossover GP I, LLC |
13D/G
|
3.9%
Reported 13D/G
· 30 Sep 2025
|
$39,822,919
2,117,103 shares
|
-$12,878,523 | 30 Sep 2025 |
| ORBIMED ADVISORS LLC |
13F
3/4/5
Company · Director, 10%+ Owner
|
—
denominator unverified
|
$107,096,409
5,693,589 shares
|
— | 30 Sep 2025 |
| AI Upstream LLC |
3/4/5
10%+ Owner
|
—
denominator unverified
|
—
5,494,410 shares
|
— | 15 Oct 2024 |
| Wellington Biomedical Innovation Master Investors (Cayman) II L.P. |
3/4/5
10%+ Owner
|
—
denominator unverified
|
—
894,733 shares
|
— | 15 Oct 2024 |
| FMR LLC |
13F
Company
|
—
denominator unverified
|
$152,105,434
8,086,413 shares
|
— | 30 Sep 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q4 2025
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
133
Shares
51,176,304
Rows available
133
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q4 2025 vs Q3 2025 Across Filers
Q3 2025 holders
94
Q4 2025 holders
133
Holder diff
39
| Investor | Q3 2025 Shares | Q4 2025 Shares | Share Diff | Share Chg % | Q3 2025 value | Q4 2025 value | Value change | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend