Prothena Corp Public Ltd Co (PRTA) stock
Close on Nov 11, 2026Market cap $448.17MP/E –Yield –
Prothena Corp Public Ltd Co grew revenue 347.4% to $52.74M over the twelve months to Sep 30, 2026. At the latest close the market valued the company at $448.17M.
Key statistics
Valuation at the latest close; fundamentals over the trailing twelve months, balances at Sep 30, 2026
Valuation
- Market cap
- $448.17M
- P/E ratio
- –
- Price to sales
- 8.50
- Price to book
- 1.67
- Dividend yield
- –
- Free cash flow yield
- –
Fundamentals
- Revenue
- $52.74M
- Net income
- -$23.96M
- EPS, diluted
- -$0.48
- Book value per share
- $5.23
- Diluted shares
- 51M
Trading
- Next earnings
- Feb 18, 2027 (estimated, after the close)
- Previous close
- $8.56
- Open
- $8.55
- Day's range
- $8.47 – $8.78
- Volume
- 392,332
- Average volume (20 days)
- 474,024
- Beta (5 years)
- 0.87
- 52-week range
- $7.73 – $11.80
- RSI (14 days)
- 53.7
- Volatility (1 year)
- 48.9%
- Relative volume
- 0.80×
- WACC
- 9.2%
On 2 of our idea lists: More cash than they're worth, Most shorted (a warning list)
Market cap history
Month-end market cap since 2012, using shares outstanding reported at the time
Total return vs. the S&P 500
Price change plus reinvested dividends, to the close on Nov 11, 2026. The S&P 500 is measured by the SPY fund.
| Period | PRTA | S&P 500 | Difference | PRTA per year | S&P 500 per year |
|---|---|---|---|---|---|
| 1 month | -1.2% | -2.4% | +1.2 pts | ||
| 3 months | -5.3% | -1.2% | −4.2 pts | ||
| Year to date | -8.6% | +12.3% | −20.9 pts | ||
| 1 year | -16.7% | +12.4% | −29.1 pts | ||
| 3 years | -73.8% | +78.8% | −152.6 pts | -36.0% | +21.4% |
| 5 years | -84.6% | +75.2% | −159.7 pts | -31.2% | +11.9% |
| 10 years | -86.3% | +311.1% | −397.4 pts | -18.0% | +15.2% |
Fifteen years at a glance
Fiscal years 2011 to 2025 and trailing twelve months, USD
Revenue
Operating income
Net income
EPS, diluted
Press releases
Releases Prothena Corp Public filed with the SEC as exhibits to Form 8-K or 6-K
- Results
- Results
- Results
- Update
- Results
- Results
About Prothena Corp Public
Pharmaceutical Preparations
Prothena Corporation plc is a clinical-stage biotechnology company that discovers and develops therapies for neurodegenerative conditions and rare peripheral amyloid diseases caused by protein dysregulation. Its research focuses on targeting pathogenic misfolded proteins while preserving normal biological function. The company's pipeline includes investigational antibody candidates such as prasinezumab for Parkinson’s disease, coramitug for ATTR amyloidosis, and BMS-986446 alongside PRX012 for Alzheimer’s disease, in addition to proprietary CYTOPE technology for intracellular disease targets. Prothena partners with global pharmaceutical corporations, including Roche, Novo Nordisk, and Bristol Myers Squibb, which advance clinical trials and commercialization to serve patient populations with limited treatment options.
Company profile, executives and historyProthena Corp Public stock: common questions
What is Prothena Corp Public's stock price?
PRTA closed at $8.73 on Nov 11, 2026, up 1.99% on the day. Over the past 52 weeks it traded between $7.73 and $11.80.
What is Prothena Corp Public's market cap?
Prothena Corp Public was worth $448.17M at the close on Nov 11, 2026: the share price times the diluted shares outstanding.
What is PRTA's P/E ratio?
Prothena Corp Public lost money over the twelve months to Sep 30, 2026 (diluted EPS -$0.48), so it has no meaningful P/E ratio.
How much revenue does Prothena Corp Public make?
Prothena Corp Public reported revenue of $52.74M for the twelve months to Sep 30, 2026, up 347.4% from a year earlier.
Does Prothena Corp Public pay a dividend?
No. Prothena Corp Public has not paid a cash dividend over the last twelve months.
When does Prothena Corp Public report earnings next?
Prothena Corp Public is expected to report Q4 FY2026 results on Feb 18, 2027, after the close. The date is estimated from its past reporting pattern until the company confirms it.
How has PRTA stock performed over the past year?
Including dividends, PRTA returned -16.7% over the past year, against +12.4% for the S&P 500.
How many PRTA shares are sold short?
8M shares were sold short at the latest FINRA report, 22.67% of the float, or 15.7 days of average trading volume.
Who are Prothena Corp Public's competitors?
Companies most similar to Prothena Corp Public by business, industry and size include AMLX, BCYC, WVE, KROS, ENTA.
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