Prothena (PRTA) vs ARS Pharmaceuticals (SPRY)
Head-to-head comparison of performance, valuation, growth, profitability and dividends. Prices delayed 15 minutes; data as of Oct 7, 2026.
Summary
Prothena (PRTA) has outperformed ARS Pharmaceuticals (SPRY) over the past year, losing 16.6% versus a loss of 57.8%. Over five years, SPRY leads with a -55.8% price change compared with -86.6% for PRTA. Prothena is the larger company by market cap ($435.3 million vs $433.6 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 | PRTA | SPRY |
|---|---|---|
| Share price | $8.48 | $4.36 |
| Market cap | $435.34M | $433.59M |
| 1-day change | +5.74% | +1.51% |
| YTD return | -11.20% | -62.58% |
| 1-year return | -16.62% | -57.79% |
| 5-year return | -86.64% | -55.78% |
| EPS (TTM) | $-0.82 | $-2.18 |
| Dividend yield | 0.00% | 0.00% |
| Annual dividend | $0.00 | $0.00 |
| 52-week high | $11.80 | $13.15 |
| 52-week low | $7.73 | $3.99 |
| Distance from 52-week high | -28.14% | -66.84% |
| Average volume | 478.70K | 1.86M |
| Shares outstanding | 51.34M | 99.45M |
| 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.
Key differences
- PRTA has outperformed SPRY by 41.2 percentage points over the past year.
PRTA vs SPRY FAQ
Which is bigger, Prothena or ARS Pharmaceuticals?
Prothena (PRTA) is larger, with a market capitalization of $435.34M compared with $433.59M for ARS Pharmaceuticals (SPRY).
Which stock has performed better over the past year, PRTA or SPRY?
PRTA returned -16.62% over the past 12 months, compared with -57.79% for SPRY (price return, excluding dividends). Past performance does not predict future results.
Are Prothena and ARS Pharmaceuticals in the same industry?
Yes. Both are classified in the Biotechnology: Pharmaceutical Preparations industry within the Health Care sector.