EcoR1 Capital UPB Position
ExitedEcoR1 Capital exited their position in Upstream Bio, Inc. (UPB) in Q2 2025, after holding the stock for 3 quarters.
The position was first reported in Q4 2024 and has been tracked across 3 quarterly 13F filings.
2 other tracked funds also hold UPB.
There is an upcoming Phase 2 readout for Verekitug in 532 days (Sep 30, 2027), making the timing of EcoR1's position particularly relevant.
Short interest stands at 15.8% of float with 2.5 days to cover, indicating significant bearish positioning against the stock.
About Upstream Bio, Inc.
Upstream Bio, Inc., a clinical-stage biotechnology company, develops treatments for inflammatory diseases that focuses on severe respiratory disorders. It develops verekitug, a monoclonal antibody that targets and inhibits the thymic stromal lymphopoietin receptor. The company also develops therapies to treat severe asthma, chronic rhinosinusitis with nasal polyps, and chronic obstructive pulmonary disease. Upstream Bio, Inc. was incorporated in 2021 and is based in Waltham, Massachusetts.
Full company profile →Short Interest
15.8%
2.5 days to cover
EcoR1 Capital UPB Position History
Frequently Asked Questions
Does EcoR1 Capital own UPB?
No. EcoR1 Capital exited their position in Upstream Bio, Inc. (UPB) in Q2 2025. They previously held the stock for 3 quarters.
How many hedge funds own UPB?
2 specialist biotech hedge funds currently hold UPB, including OrbiMed Advisors, Deep Track Capital. When 3 or more specialist funds hold the same stock, BiotechEdge flags it as a convergence signal.
When did EcoR1 Capital first buy UPB?
EcoR1 Capital's position in UPB was first reported in Q4 2024. 13F filings are reported with a 45-day delay, so the actual purchase may have occurred earlier in the quarter.
Is EcoR1 Capital's UPB position increasing or decreasing?
EcoR1 Capital completely exited their UPB position in the most recent quarter.
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