Listing facts
- SEC issuer name
- PROTHENA CORP PUBLIC LTD CO
- Ticker
- PRTA
- Exchange
- Nasdaq
- Instrument family
- Ordinary share
- SEC issuer CIK
- 0001559053
- Listing source refreshed
- 2026-09-13
- Reviewed security class
- Ordinary Shares, par value $0.01 per share
Market summary
Completed-session reference prices from IEX for Oct 2, 2026.
IEX historical data reflects IEX activity only and is presented as a source-scoped reference point, not as consolidated U.S. market history. Prices are unadjusted. Price returns exclude dividends and are not total returns. Historical statistics appear only when the retained source-session chain is complete and no split-like share-basis discontinuity is detected for that calculation window.
Data provided for free by IEX. By accessing or using IEX Historical Data, you agree to the IEX Historical Data Terms of Use.
Price history
Recent completed-session closing-price history for this listing. The chart shows raw, unadjusted single-exchange reference observations rather than a consolidated U.S. market close.
Screened reference metrics
These percentage measures use the same qualified observation window and normalize only explicitly registered positive split events. They are reference metrics, not total returns or benchmark-relative performance.
About this market data
IEX historical data reflects IEX activity only and is presented as a source-scoped reference point, not as consolidated U.S. market history.
Screened reference metrics use K9-qualified IEX reference history and only explicitly registered positive split events. They do not assert complete split history, consolidated U.S. market performance, or canonical adjusted prices.
Data provided for free by IEX. By accessing or using IEX Historical Data, you agree to the IEX Historical Data Terms of Use.
The raw chart can show a discontinuity around a stock split because it is intentionally unadjusted. The screened metrics use only explicitly registered positive split events and do not assert complete split history.
SEC insider holdings snapshot
Current value of the supported direct positions Grizzly Bulls can trace through SEC ownership filings and value for this company. Coverage may be incomplete, so this is not total insider ownership.
Covered reporting owners
SEC-reported relationship information for the owners represented in this snapshot. When available, the share counts and current values below refer only to the supported positions included in the company total. They are not estimates of total personal wealth.
Recent insider transactions
Recent supported direct, non-derivative transactions reported in SEC ownership filings. These are historical transactions, not current cash or personal wealth. Reported prices are shown when the filing provides them; no gross proceeds are calculated here.
Showing up to 12 recent supported transactions. Filings can be omitted when a legal security cannot be resolved safely. Amended filings can appear separately because this view does not infer transaction supersession across filings.
Fundamental lens
Four transparent questions from retained financial evidence. Each result stands on its own; Grizzly Bulls does not combine them into a score, ranking, or recommendation.
Trailing-twelve-month net income is negative. As of 2026-06-30.
The retained reader does not currently have the required trailing-twelve-month fact.
Reported current assets exceed reported current liabilities on the latest comparable retained balance sheet. As of 2026-06-30.
Comparable retained change history is not available through this reader.
How this lens works
Profitability uses only the sign of retained trailing-twelve-month net income. Cash generation uses only the sign of retained trailing-twelve-month free cash flow, defined as operating cash flow less capital expenditures.
Liquidity compares current assets with current liabilities only when both are retained for the same reporting date. It does not infer liquidity from differently dated balance sheets.
Recent operating direction uses the latest supported material financial event when comparable history exists. The existing change methodology requires at least a 10% absolute change or a sign/zero transition and compares quarterly results only with the same fiscal quarter year over year.
Statistics
Reproducible trailing, quarterly, and annual statistics from retained SEC financials. Growth and return measures appear only when the required reporting periods align; missing denominators are omitted rather than estimated.
Trailing, quarterly, and annual profitability, return, and growth measures derived from retained SEC financials.
Latest annual liquidity measures using same-period reported current assets and current liabilities.
Trailing cash generation plus latest annual dividends and share repurchases where reported.
Historical financial statistics are descriptive accounting measures, not rankings or investment recommendations.
Financials
SEC-reported financial statement history with filing dates preserved. Annual view retains up to four fiscal years; quarterly view retains up to five fiscal quarters. Missing cells mean a supported fact is unknown and are not treated as zero.
Income statement
| Metric | TTM · 2026-06-30 | FY 2025 · 2025-12-31 | FY 2025 · 2024-12-31 | FY 2025 · 2023-12-31 | FY 2024 · 2022-12-31 |
|---|---|---|---|---|---|
| Revenue | $54.53M Filed 2026-08-06 | $9.68M Filed 2026-02-27 | $135.16M Filed 2026-02-27 | $91.37M Filed 2026-02-27 | $53.91M Filed 2025-02-27 |
| Operating expenses | $110.04M Filed 2026-08-06 | $224.32M Filed 2026-02-27 | $289.72M Filed 2026-02-27 | $282.41M Filed 2026-02-27 | $185.46M Filed 2025-02-27 |
| Operating income | -$55.51M Filed 2026-08-06 | -$214.64M Filed 2026-02-27 | -$154.56M Filed 2026-02-27 | -$191.04M Filed 2026-02-27 | -$131.56M Filed 2025-02-27 |
| Pretax income | -$44.35M Filed 2026-08-06 | -$200.83M Filed 2026-02-27 | -$128.93M Filed 2026-02-27 | -$160.48M Filed 2026-02-27 | -$125.61M Filed 2025-02-27 |
| Income tax expense | -$358,000 Filed 2026-08-06 | $43.26M Filed 2026-02-27 | -$6.62M Filed 2026-02-27 | -$13.45M Filed 2026-02-27 | -$8.66M Filed 2025-02-27 |
| Net income | -$43.99M Filed 2026-08-06 | -$244.09M Filed 2026-02-27 | -$122.31M Filed 2026-02-27 | -$147.03M Filed 2026-02-27 | -$116.95M Filed 2025-02-27 |
| Diluted EPS | Unavailable | -$4.53 Filed 2026-02-27 | -$2.27 Filed 2026-02-27 | -$2.76 Filed 2026-02-27 | -$2.47 Filed 2025-02-27 |
| Diluted shares | Unavailable | 53.83M Filed 2026-02-27 | 53.77M Filed 2026-02-27 | 53.22M Filed 2026-02-27 | 47.37M Filed 2025-02-27 |
Balance sheet
| Metric | FY 2025 · 2025-12-31 | FY 2025 · 2024-12-31 | FY 2025 · 2023-12-31 | FY 2024 · 2022-12-31 |
|---|---|---|---|---|
| Cash | $307.53M Filed 2026-02-27 | $471.39M Filed 2026-02-27 | $618.83M Filed 2026-02-27 | $710.41M Filed 2025-02-27 |
| Current assets | $315.19M Filed 2026-02-27 | $485.41M Filed 2026-02-27 | $639.28M Filed 2025-02-27 | $719.1M Filed 2024-02-22 |
| Current liabilities | $40.84M Filed 2026-02-27 | $48.5M Filed 2026-02-27 | $56.89M Filed 2025-02-27 | $50.15M Filed 2024-02-22 |
| Total assets | $326.8M Filed 2026-02-27 | $547.11M Filed 2026-02-27 | $696.38M Filed 2025-02-27 | $758.04M Filed 2024-02-22 |
| Total liabilities | $46.33M Filed 2026-02-27 | $60.18M Filed 2026-02-27 | $135.02M Filed 2025-02-27 | $135.99M Filed 2024-02-22 |
| Stockholders’ equity | $280.47M Filed 2026-02-27 | $486.93M Filed 2026-02-27 | $561.37M Filed 2025-02-27 | $622.04M Filed 2024-02-22 |
Cash flow
| Metric | TTM · 2026-06-30 | FY 2025 · 2025-12-31 | FY 2025 · 2024-12-31 | FY 2025 · 2023-12-31 | FY 2024 · 2022-12-31 |
|---|---|---|---|---|---|
| Operating cash flow | -$60.05M Filed 2026-08-06 | -$163.58M Filed 2026-02-27 | -$150.05M Filed 2026-02-27 | -$133.91M Filed 2026-02-27 | -$108.82M Filed 2025-02-27 |
| Depreciation & amortization | $828,000 Filed 2026-08-06 | $895,000 Filed 2026-02-27 | $893,000 Filed 2026-02-27 | $928,000 Filed 2026-02-27 | $744,000 Filed 2025-02-27 |
Calculated from the latest TTM financials
Source: SEC filings. Financial facts retain filing dates and are shown only when the retained source and period alignment support them.