Upstream Bio, Inc. (UPB) Stock

Upstream Bio, Inc. (UPB) is a Healthcare stock trading at $6.96 (as of 2026-08-21), with a market capitalization of $378.76M. Figures are sourced from first-party U.S. SEC EDGAR filings and market data.

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.

Understand Upstream Bio, Inc.: how it makes money

Upstream Bio develops monoclonal antibody and other therapies for severe inflammatory respiratory diseases, including verekitug for conditions such as severe asthma, chronic rhinosinusitis with nasal polyps, and chronic obstructive pulmonary disease, aiming to generate revenue later through clinical and commercial success and any future collaboration income.

Because it is a clinical-stage biotechnology company with 0.0B revenue in the latest reported quarter, its near-term profit model depends on ongoing clinical development translating into future commercial value or non-zero collaboration revenue, while operating expenses drive a large operating loss in the meantime.

Revenue by segment (latest quarter)
Collab	$0.0B
Related Party	$0.0B

Business quality (Weak): Clear development focus and measurable trial operational updates, but currently no reported revenue, so progress and trial outcomes are the key inflection points for the business model.

Bull case

Trial execution indicators are tracked, including VENTURE Trial Enrollment Progress (More than Sixty Percent to Date) at 60.0%: On-time enrollment and study continuity can help maintain momentum for Phase 2 development.
High retention in the Phase 2 VALOUR Long-Term Extension Study, at 90.0%: Strong retention can support data completeness for long-term study endpoints.

Bear case

No revenue reported in the latest quarter (Revenue of 0.0B, including Collaboration Revenue of 0.0B): The company may continue to rely on external funding until clinical outcomes lead to monetizable products or meaningful collaborations.
Large operating loss in the latest quarter (Operating margin of -4218.1%): Sustained losses can increase dilution or financing risk if clinical milestones or partnering do not materialize on the expected timeline.

Valuation — source: SEC EDGAR (first-party)
Price	$6.96
Market Cap	$378.76M
Price / Book	1.40
Price / Sales	107.48
FCF Yield	-49.2%

Profitability & Growth — source: SEC EDGAR
Revenue (TTM)	$2.85M
Net Margin	-5026.0%
Revenue Growth (YoY)	20.4%
EPS Growth (YoY)	-52.3%
FCF Growth (YoY)	123.6%

Financial Health — source: SEC EDGAR
Altman Z-Score	14.57 (safe)

Valuation vs Sector & Industry
Sector P/E (Healthcare)	21.7
Industry P/E (Pharmaceutical Products)	17.2

Smart-Money Activity — SEC Form 4 / 13F / Congressional disclosures
Top Institutional Holder	FMR LLC ($72.91M)
Institutional Holders Tracked	10

Company
Sector	Healthcare
Industry	Pharmaceutical Products
CEO	E. Rand Sutherland
Employees	52
Country	US
IPO Date	2024-10-11

Related Companies (Business model: Biotech (Clinical / Commercial-Stage); 8 closest by market cap; US-domiciled)

Data as of 2026-08-21.

Figures sourced from U.S. Securities and Exchange Commission (SEC EDGAR) filings and market data. Not personalized investment advice.