Prothena Corporation plc (PRTA)
Healthcare
Biotechnology
8.10 $
-3.4%
vs. previous close
Closing price · As of: 31. Jul 2026
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Appears in These Scanners
This stock currently matches 5 of our scanner strategies — each hit links to the scanner.
Quality & Balance Sheet
Only genuine hits from verified scanners count; pure ranking metrics (P/E, P/S, and similar, which just sort the whole universe) don't count as a hit. View all scanners
Basics
Market Cap
The value of the entire company on the market: share price times total shares outstanding.
0.4$B
Shares Outstanding
Total number of shares issued. Price times share count gives market cap.
52Mio.
Float
Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
70.1%
Beta
Volatility versus the overall market: 1 = moves like the market, 2 = twice as much, under 1 = calmer than the market.
-0.3
Performance
Perf. 1M
Price performance over the last month.
-0.10%
Perf. 3M
Price performance over the last 3 months.
7.70%
Perf. 6M
Price performance over the last 6 months.
2.90%
YTD Performance (%)
Price performance since the start of the year (Year to Date).
0.00%
52-Week-High Distance
How far the price sits below its highest point over the last 52 weeks. 0% means the stock is at its year high.
-21.4%
Perf. 1Y
Price performance over the last 12 months.
55.12%
Perf. 3Y
Price performance over the last 3 years.
-86.30%
Perf. 5Y
Price performance over the last 5 years.
-80.77%
Valuation
P/E
Price-to-earnings ratio: how many years of profit does the stock cost? The lower, the cheaper the valuation. No earnings means no P/E.
–
Forward P/E
P/E based on expected earnings for the next 12 months instead of past earnings — analysts' bet on the future.
10.6
PEG
P/E divided by expected earnings growth: puts valuation in relation to growth. Around 1 is considered fair, well above that is pricey.
0.8
P/B
Price-to-book ratio: market value relative to book equity.
–
P/S
Price-to-sales ratio: market value divided by annual sales. Important for companies that aren't (yet) profitable.
7.3
EV/EBITDA
Enterprise value including debt (EV) relative to operating profit before depreciation and amortization (EBITDA) — more comparable than P/E because debt counts too. Extreme values arise when EBITDA is near zero.
-3.6
Price/FCF
Market value divided by free cash flow: how many years of freely available cash does the stock cost? More honest than P/E because cash flow is harder to dress up.
–
Profitability
Gross Margin
Gross margin: what's left of sales after only direct production costs are deducted — the product's pricing power.
-66.8%
EBIT Margin
EBIT margin: operating profit as a percentage of sales — the earning power of the core business before interest and taxes.
–
Net Margin
Net margin: what's left of sales as profit after ALL costs, interest, and taxes.
-260.9%
Return on Equity
Return on equity: how much profit does the company generate per year on shareholders' equity?
-40.3%
Return on Assets
Return on assets: how much profit the company generates from its total assets (equity and debt combined).
-13.8%
Balance Sheet & Safety
Equity Ratio
Equity ratio: equity as a share of total assets. The higher, the more resilient the balance sheet.
–
Debt/Equity
Leverage ratio: financial debt divided by equity. Under 1 is generally seen as solid; negative values mean negative equity.
–
Altman Z″
Edward Altman's bankruptcy early-warning score. We use the Z″ variant, built from four balance-sheet ratios — it is designed for service companies and non-manufacturers and uses book value instead of market value. On that scale: below 1.1 = danger zone, 2.6 and up = safe zone, in between a grey area. Because the classic Altman Z is calculated differently, the two numbers are not directly comparable. The formula does not fit banks, insurers, or real-estate stocks.
4.09
Piotroski
Balance-sheet health check by Joseph Piotroski: 9 yes/no criteria on profit, cash flow, leverage, and efficiency. 7+ is very solid, under 3 is a red flag.
6 out of 9
Growth
Sales Growth Last Quarter
Sales growth in the most recently reported quarter versus the same quarter a year ago (YoY).
0.00%
EPS Growth Last Quarter
Growth in earnings per share in the most recently reported quarter versus the same quarter a year ago (YoY).
0.00%
Sales Growth (Year)
Sales growth in the last fiscal year versus the year before.
-92.83%
Forward Sales Growth
Sales growth analysts expect over the next 12 months — an estimate, not a guarantee.
-73.60%
Forward EPS Growth
Earnings-per-share growth analysts expect over the next 12 months — an estimate, not a guarantee.
-2,720.00%
Dividend
This stock currently pays no dividend.
Quality & Screener
Stage
Weinstein phases 1 through 4: 1 = basing, 2 = uptrend (the only buy phase), 3 = topping, 4 = downtrend. Measured against the 30-week line.
4
RS Rating
Relative strength from 1 to 99: an RS of 95 means the stock has outperformed 95% of all stocks.
64
EPS Rating
Earnings growth rating from 1 to 99 versus all stocks — high values mean above-average earnings growth.
42
Piotroski
Balance-sheet health check by Joseph Piotroski: 9 yes/no criteria on profit, cash flow, leverage, and efficiency. 7+ is very solid, under 3 is a red flag.
6 out of 9
Fundamental Rating
Our own Fundamental Rating: 0 to 100 points with an A+ to F grade. 50 points is the average across the universe, 100 the best possible score. It scores growth, earnings surprises, analyst estimates, margins, cash flow, and balance-sheet safety — every stock percentile-ranked against all others. Grades: A+ from 95, A from 75, B from 55, C from 45, D from 25, E from 5, F below.
C (46 out of 100)
Altman Z″
Edward Altman's bankruptcy early-warning score. We use the Z″ variant, built from four balance-sheet ratios — it is designed for service companies and non-manufacturers and uses book value instead of market value. On that scale: below 1.1 = danger zone, 2.6 and up = safe zone, in between a grey area. Because the classic Altman Z is calculated differently, the two numbers are not directly comparable. The formula does not fit banks, insurers, or real-estate stocks.
4.09
AI Rating
–Not yet rated — we only show a category once an SEC-backed file with at least two cited passages is available. How the Rating Is Built
Analysts & Price Target
Current Price
8.10 $
Price Target (average)
21.40 $
The price target sits 164.2% above the current price.
Combined picture of the price targets and recommendations of every analyst covering the stock. Price targets are expectations for the next 12 months, not promises — and they often follow the price rather than predict it.
Next Reporting Date
3. Aug 2026
· after the close
· Q2 2026
- Expected Earnings per Share
- -0.39 $
Expected date of the next quarterly or annual figures. Dates do shift occasionally — only the invitation issued by the company is binding.
Quarterly Figures
| Quarter | EPS (Earnings Per Share) | EPS YoY (%) | Sales ($M) | Sales YoY (%) | Net Margin (%) | OCF ($M) | FCF ($M) |
|---|---|---|---|---|---|---|---|
| 2024: Q4 | -1.08 | – | 2 | 571.80 | -2,729.90 | -48 | -48 |
| 2025: Q1 | -1.12 | – | 3 | 5,556.00 | -2,128.50 | -53 | -53 |
| 2025: Q2 | -2.34 | -292.30 | 4 | -96.70 | -2,845.40 | -46 | -46 |
| 2025: Q3 | -0.68 | – | 2 | 149.00 | -1,513.10 | -41 | -41 |
| 2025: Q4 | -0.40 | – | 0 | -99.00 | -102,804.80 | -23 | -23 |
| 2026: Q1 | 0.60 | – | 51 | 1,706.40 | 64.10 | 29 | 29 |
What Do These Terms Mean?
- EPS (Earnings Per Share):
- Quarterly profit divided by the total share count — how much of the profit works out to a single share.
- YoY (Year over Year):
- Change versus the same quarter a year ago — this is how you compare without seasonal distortion (e.g. the holiday shopping season).
- Sales:
- All revenue for the quarter, before any costs are deducted — the top line of the income statement.
- Net Margin:
- What percentage of sales is left over as profit in the end. Negative means the company is posting a loss.
- OCF (Operating Cash Flow):
- The cash that actually flows into the till from the core business during the quarter — harder to dress up than book profit.
- FCF (Free Cash Flow):
- Operating cash flow minus capital expenditures — the money that's genuinely free to use, say for paying down debt, buybacks, or dividends.
About the Company
Prothena Corporation plc, a late-stage clinical biotechnology company, focuses on discovery and development of novel therapies to treat diseases caused by protein dysregulation. Its product pipeline includes Prasinezumab, an investigational humanized monoclonal antibody which is in Phase 3 clini…
| Employees | 67 |
|---|---|
| Headquarters | Dublin, Ireland |
| Website | prothena.com |
| IPO Date | 21. Dec 2012 |
Management
| Name | Title | Birth Year |
|---|---|---|
| Gene G. Kinney Ph.D. | President, CEO & Director | 1969 |
| Tran B. Nguyen M.B.A. | Chief Financial Officer | 1974 |
| Brandon S. Smith | Chief Operating Officer | 1975 |
| Wagner M. Zago Ph.D. | Chief Scientific Officer | 1973 |
| Chad H. Swanson Ph.D. | Chief Development Officer | – |
| Karin L. Walker CPA | Chief Accounting Officer & Controller | 1963 |
| Mark C. Johnson C.F.A. | Vice President of Investor Relations | – |
| Michael J. Isaacs | General Counsel & Corporate Secretary | – |
| Phillip Dolan | Sr. Director & Head of Exploratory Research | – |
| Annie Evans Kingston | Chief Strategy Officer | – |
Executives per the latest required filings; titles kept in their original language. Source: fundamental data.
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 29. Jul 2026 | Kingston Anne Evans | Chief Strategy Officer | Sell | 7,662 | 8.47 | 64,919 |
| 29. Jul 2026 | Isaacs Michael John | General Counsel & Company Sec. | Sell | 8,386 | 8.47 | 71,055 |
| 28. Jul 2026 | Zago Wagner M. | Chief Scientific Officer | Other | 51,000 | 8.56 | 436,560 |
| 28. Jul 2026 | Zago Wagner M. | Chief Scientific Officer | Other | 51,000 | – | – |
| 28. Jul 2026 | Walker Karin L | Chief Accounting Officer | Other | 15,000 | 8.56 | 128,400 |
| 28. Jul 2026 | Walker Karin L | Chief Accounting Officer | Other | 15,000 | – | – |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 3,467 | 8.56 | 29,678 |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 40,800 | 8.56 | 349,248 |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 51,000 | – | – |
| 28. Jul 2026 | Smith Brandon S. | Chief Operating Officer | Other | 78,000 | 8.56 | 667,680 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character.
View all insider transactions →Chart
Interactive price chart (TradingView).
Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.