Security key
91678A107
- Security type / class
- Equity / Common Stock
- Total 13F shares
- 42,074,592
- Total 13F value
- $690,108,943
- Share change
- +39,613,174
- SEC-reported price per share
- $16.44
- Number of holders
- 70
- Value change
- +$649,643,232
- Number of buys
- 66
- Shares outstanding
- 54,419,669
Holder snapshot
5 signals
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q4 2024
Institutions
70
Top holders
10
UPB full security history
Ownership snapshot
Full 13F holder table
Upstream Bio, Inc. SEC filings
Upstream Bio, Inc. company facts
Broader feeds
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
AI Upstream LLC
Disclosed value leader
—
Comparable rows
0/3
Latest evidence
15 Oct 2024
3/4/5
Some rows are evidence-backed but not safely comparable across classes.
3 rows are not safely comparable across share classes.
Quick read
SEC ownership evidence is available, but the rows are not safely comparable across share classes.
0 of 3 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 AI Upstream LLC's linked filing trail.
Detailed SEC evidence table Showing 1-3 of 3 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| AI Upstream LLC |
3/4/5
10%+ Owner
|
—
class O/S missing
|
—
5,494,410 shares
|
— | 15 Oct 2024 |
| ORBIMED ADVISORS LLC |
3/4/5
Director, 10%+ Owner
|
—
class O/S missing
|
—
4,554,873 shares
|
— | 15 Oct 2024 |
| Wellington Biomedical Innovation Master Investors (Cayman) II L.P. |
3/4/5
10%+ Owner
|
—
class O/S missing
|
—
894,733 shares
|
— | 15 Oct 2024 |
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 2024
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
70
Shares
42,074,592
Rows available
70
| 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 2024 vs Q3 2024 Across Filers
Q3 2024 holders
0
Q4 2024 holders
70
Holder diff
70
| Investor | Q3 2024 Shares | Q4 2024 Shares | Share Diff | Share Chg % | Q3 2024 value | Q4 2024 value | Value change | Value Chg % |
|---|