Aldeyra Therapeutics (ALDX) vs Mereo BioPharma Group (MREO)
Head-to-head comparison of performance, valuation, growth, profitability and dividends. Prices delayed 15 minutes; data as of Oct 9, 2026.
Summary
Mereo BioPharma Group (MREO) has outperformed Aldeyra Therapeutics (ALDX) over the past year, losing 83.3% versus a loss of 83.8%. Over five years, MREO leads with a -83.9% price change compared with -89.0% for ALDX. Mereo BioPharma Group is the larger company by market cap ($55.9 million vs $55.3 million), about 1.0 times the size.
Summary generated from market data by MetaCap's automated system. Methodology
Relative performance
Percent change in share price from the first common trading day shown; excludes dividends.
Head-to-head
| Metric | ALDX | MREO |
|---|---|---|
| Share price | $0.9163 | $0.3499 |
| Market cap | $55.28M | $55.88M |
| 1-day change | -3.31% | -6.74% |
| YTD return | -82.31% | -16.09% |
| 1-year return | -83.84% | -83.34% |
| 5-year return | -89.01% | -83.95% |
| EPS (TTM) | $-0.38 | $-0.20 |
| Dividend yield | 0.00% | 0.00% |
| Annual dividend | $0.00 | $0.00 |
| 52-week high | $5.93 | $2.37 |
| 52-week low | $0.862 | $0.20 |
| Distance from 52-week high | -84.55% | -85.24% |
| Analyst consensus | strong_buy | none |
| Avg. price target upside | +620.29% | +460.16% |
| Average volume | 1.18M | 4.04M |
| Shares outstanding | 60.33M | 159.69M |
| Employees | 6 | 39 |
| Sector | Health Care | Health Care |
| Industry | Biotechnology: Pharmaceutical Preparations | Biotechnology: Pharmaceutical Preparations |
Highlighted cells mark the higher value for growth, returns, margins and yield, and the lower value for P/E ratios. Highlighting is a mechanical comparison, not a recommendation.
About Aldeyra Therapeutics
ALDX stock →Aldeyra Therapeutics, Inc., a biotechnology company, discovers and develops therapies designed to treat immune-mediated diseases. Its lead product candidate is reproxalap, a reactive aldehyde species (RASP) modulator, which is in Phase III clinical trial for the treatment of dry eye disease and allergic conjunctivitis; and ADX-2191, a dihydrofolate reductase inhibitor for the treatment of primary vitreoretinal lymphoma and retinitis pigmentosa.
Health Care · Biotechnology: Pharmaceutical Preparations · 6 employees
About Mereo BioPharma Group
MREO stock →Mereo BioPharma Group plc, a biopharmaceutical company, develops and commercializes therapeutics for the treatment of rare diseases in the United Kingdom and the United States. The company develops Setrusumab, an antibody for the treatment of osteogenesis imperfecta; Alvelestat, an oral small molecule that is in Phase II clinical trial to treat Alpha-1 anti-trypsin deficiency associated lung disease; and Vantictumab, an anti-FZD monoclonal antibody for the treatment of autosomal dominant osteopetrosis type 2.
Health Care · Biotechnology: Pharmaceutical Preparations · 39 employees
ALDX vs MREO FAQ
Which is bigger, Aldeyra Therapeutics or Mereo BioPharma Group?
Mereo BioPharma Group (MREO) is larger, with a market capitalization of $55.88M compared with $55.28M for Aldeyra Therapeutics (ALDX).
Which stock has performed better over the past year, ALDX or MREO?
MREO returned -83.34% over the past 12 months, compared with -83.84% for ALDX (price return, excluding dividends). Past performance does not predict future results.
Are Aldeyra Therapeutics and Mereo BioPharma Group in the same industry?
Yes. Both are classified in the Biotechnology: Pharmaceutical Preparations industry within the Health Care sector.