By CapitalSnitch Research Desk · updated Oct 11, 2026 · data from SEC filings and official Congress disclosures
Upstream Bio, Inc. officers and board members have only been selling lately: five insiders sold about $105,000 of stock over 12 months, with no open-market purchases.
Selling on its own is common and often pre-planned (10b5-1 plans, taxes, diversification), so it matters more when it is unusually heavy or broad.
On the institutional side, 149 funds reported holding UPB at the end of Q2 2026, and more funds bought than sold. 3 quarters in a row of net selling by insiders. Insiders bought in 0 of the last 7 full quarters.
Are insiders buying or selling UPB stock?
In the last 12 months Upstream Bio, Inc. insiders made open-market purchases worth about $0 and sales worth about $105,000. Data comes from SEC Form 4 filings, updated every 30 minutes on CapitalSnitch.
When was the last insider trade in UPB?
The most recent open-market insider trade in UPB was filed on 2026-09-17.
How many institutions own UPB?
149 investment managers reported holding UPB in SEC Form 13F filings for Q2 2026.
Has any member of Congress traded UPB?
No congressional trades in UPB were reported in the past two years. The full list is free on CapitalSnitch.
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Public-record data for research and education, not investment advice. Insider sales are often pre-planned (10b5-1).
Congress data: Data derived from public disclosures filed under the Ethics in Government Act and the STOCK Act, republished free for public transparency and news reporting. Disclosures may lag the trade by 45 days or more and show amounts only as ranges. This data may not be used for credit rating, loan underwriting, solicitation of money (political, charitable or other), direct-mail or commercial targeting (5 U.S.C. 13107).