# Prothena Corporation plc (PRTA) fundamentals

Data as of 2026-11-04. NASDAQ, United States. Sector: Healthcare / Biotechnology. Price $8.21, market value $421 million.

## Valuation
- **P/E (trailing): n/a** (negative earnings). Prothena Corporation plc reported negative earnings over the last twelve months, so the P/E is not meaningful; use price-to-sales, EV/EBITDA and free-cash-flow yield instead.
- **Price / sales: 7.7×**. Each dollar of revenue is priced at 7.7×.
- **Price / book: 1.5×**. The shares trade at 1.5× book value; book value is a meaningful part of the valuation.

## Profitability
- **Operating margin: -101.8%**. Operating margin is negative: the business loses money before interest and tax.
- **Return on equity: -87.0%**. Return on equity is negative because earnings are negative.
- **Return on assets: -13.5%**. Each dollar of assets produces -13.5% of profit.

## Growth
- **Revenue growth (1 yr): -92.8%** (3-yr -43.6%/yr, 5-yr 62.6%/yr). Revenue fell 92.8% over the last year, against 62.6% a year compounded over five years: growth is slowing.
- **EPS growth (1 yr): -99.6%**. Earnings per share fell 99.6%, slower than revenue, so margins compressed.

## Financial health
- **Current ratio: 7.72** (quick 7.72). Current assets cover the next year's liabilities 7.72 times.
- **Altman Z-score: 5.53**. A Z-score of 5.53 places the company in the safe zone for bankruptcy risk.
- **Piotroski F-score: 1/9**. 1 of 9 checks pass: weak or deteriorating financials.

## Dividends
- **Dividend: none**. Prothena Corporation plc does not currently pay a dividend.

## Price and momentum
- **Total return (1 yr): -22.1%** (YTD -14.0%, 3-mo -3.3%). The shares are down 22.1% over twelve months including dividends.
- **From 52-week high: -30.4%** (6.2% above the low). Trading 30% below its 52-week high, deep in a drawdown.
- **200-day average: below**. The price sits below its 200-day moving average, the usual definition of a downtrend.
- **RSI (14-day): 44**. An RSI of 44 is neutral.
- **Beta (1 yr): 1.08** (volatility 48%). Beta of 1.08 against the S&P 500: the shares move roughly with the market.

Live score and charts: https://foliofundamentals.com/analyzer?s=PRTA · Page: https://foliofundamentals.com/stocks/prta

Not investment advice.