PRTA · NASDAQ
Prothena (PRTA) Stock Price & Fundamentals
Prothena (PRTA) closed at $1,131.01 on Oct 9, 2026, up 0.93% from the previous close of $1,120.62.
Share price, past year
1Y +29.74%Monthly closing prices
| Date | Close |
|---|---|
| Oct 9, 2026 | $1,131.01 |
| Sep 30, 2026 | $1,097.42 |
| Aug 31, 2026 | $1,070.12 |
| Jul 31, 2026 | $1,068.93 |
| Jun 30, 2026 | $1,100.93 |
| May 29, 2026 | $1,055.00 |
| Apr 30, 2026 | $1,052.70 |
| Mar 31, 2026 | $1,031.84 |
| Feb 27, 2026 | $959.52 |
| Jan 30, 2026 | $963.15 |
| Dec 31, 2025 | $977.73 |
| Nov 28, 2025 | $894.92 |
| Oct 31, 2025 | $904.30 |
Key statistics
- Market cap
- $58.52B
- P/E (TTM)
- —
- EPS (TTM)
- −$0.83
- Revenue (TTM)
- $54.53M
- Net income (TTM)
- −$43.99M
- Shares outstanding
- 51.7M
- Dividend yield
- —
- 52-week range
- $867.71 – $1,131.01
Prothena's market cap is $58.52B, based on a share price of $1,131.01 and 51.7M shares outstanding as of Jun 30, 2026.
Financials
Prothena reported revenue of $9.68M for fiscal 2025, down 92.83% from fiscal 2024.
Prothena reported a net loss of $244.09M in fiscal 2025.
Annual revenue
| Fiscal year | Revenue | Growth | Net income | Net margin | EPS (diluted) | Free cash flow |
|---|---|---|---|---|---|---|
| FY2025ended Dec 31, 2025 | $9.68M | −92.8% | −$244.09M | −2,520.6% | −$4.53 | — |
| FY2024ended Dec 31, 2024 | $135.16M | +47.9% | −$122.31M | −90.5% | −$2.27 | — |
| FY2023ended Dec 31, 2023 | $91.37M | +69.5% | −$147.03M | −160.9% | −$2.76 | — |
| FY2022ended Dec 31, 2022 | $53.91M | −73.1% | −$116.95M | −217.0% | −$2.47 | — |
| FY2021ended Dec 31, 2021 | $200.58M | +23,414.3% | $66.98M | 33.4% | $1.38 | — |
| FY2020ended Dec 31, 2020 | $853.00K | +4.8% | −$111.14M | −13,029.8% | −$2.78 | — |
| FY2019ended Dec 31, 2019 | $814.00K | −14.8% | −$77.68M | −9,542.6% | −$1.95 | — |
| FY2018ended Dec 31, 2018 | $955.00K | −96.5% | −$155.65M | −16,297.9% | −$3.93 | — |
| FY2017ended Dec 31, 2017 | $27.52M | +2,508.4% | −$153.24M | −556.8% | −$4.07 | — |
| FY2016ended Dec 31, 2016 | $1.06M | — | −$160.11M | −15,176.1% | −$4.66 | — |
| Quarter | Revenue | Net income | EPS (diluted) |
|---|---|---|---|
| Q2 FY2026ended Jun 30, 2026 | $1.01M | −$18.58M | −$0.36 |
| Q1 FY2026ended Mar 31, 2026 | $51.08M | $32.72M | $0.60 |
| Q4 FY2025ended Dec 31, 2025 | $21.00K | −$21.59M | −$0.39 |
| Q3 FY2025ended Sep 30, 2025 | $2.42M | −$36.54M | −$0.68 |
| Q2 FY2025ended Jun 30, 2025 | $4.42M | −$125.77M | −$2.34 |
| Q1 FY2025ended Mar 31, 2025 | $2.83M | −$60.20M | −$1.12 |
| Q4 FY2024ended Dec 31, 2024 | $2.12M | −$57.96M | −$1.05 |
| Q3 FY2024ended Sep 30, 2024 | $970.00K | −$59.00M | −$1.10 |
Company profile
- Name
- Prothena Corporation plc
- Ticker
- PRTA
- Exchange
- NASDAQ
- Industry (SEC SIC)
- Pharmaceutical Preparations
- Headquarters
- 77 Sir John Rogerson'S Quay, Block C, Grand Canal Docklands, Dublin 2, L2 D02 VK60
- Incorporated in
- L2
- Fiscal year ends
- December
- SEC CIK
- 0001559053
Recent SEC filings
- Oct 2, 2026
- Aug 6, 2026
- Aug 6, 2026
- May 15, 2026
- May 7, 2026
- May 7, 2026
- Feb 27, 2026
- Feb 27, 2026
Frequently asked questions
What is Prothena's stock price?
Prothena (PRTA) closed at $1,131.01 on Oct 9, 2026, up 0.93% from the previous close of $1,120.62.
What is Prothena's market cap?
Prothena's market cap is $58.52B, based on a share price of $1,131.01 and 51.7M shares outstanding as of Jun 30, 2026.
How much revenue does Prothena make?
Prothena reported revenue of $9.68M for fiscal 2025, down 92.83% from fiscal 2024.
Does Prothena pay a dividend?
Prothena's recent filings report no dividends declared over the last four quarters.
Sources and methodology
Fundamentals come from Prothena Corporation plc's filings with the SEC (EDGAR XBRL company facts). Fourth-quarter figures that companies don't report separately are calculated as the fiscal year minus the first three quarters. Trailing twelve-month (TTM) figures sum the latest four quarters. Prices are generated sample data for development. Last updated Oct 9, 2026. Data sources and disclosures