13F

Stock

Upstream Bio, Inc.

UPB · held by 6 managers

Reported value

$4.3M

Holders

6

+0 new · −0 exited

Holders’ est. mark

$668.8K

Price effect on 2 books still in the name

Largest holder

$1.65M

MORGAN STANLEY

Holder count by quarter

Who holds it

Notable only
InvestorSharesValueEst. markChange
MORGAN STANLEY87.5K$1.65MHeld
BARCLAYS PLC85.3K$1.6M$668KAdded$539.8K
BANK OF AMERICA CORP /DE/55.5K$1.04MHeld
Essential Partners LLC97$1.82K$760Added$760
Allworth Financial LP67$1.26KHeld
IFP Advisors, Inc2$38Held

Positions as of Q3 2025. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.