Prothena Corporation plc
PRTA Healthcare Biotechnology
Prothena Corporation plc’s revenue for fiscal 2025 (year ended December 2025) was $9.7 million, down 92.8% from fiscal 2024. In the quarter to June 2026, revenue fell 77.2%, EPS grew 84.6% and free cash flow grew 44.6%, each against the same quarter a year earlier. Insiders bought in the last twelve months.
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Prothena Corporation plc (PRTA) Piotroski F-score
Prothena Corporation plc's Piotroski F-score for fiscal 2025 is 2 out of 9: 2 of nine tests of profitability, leverage and efficiency passed, down from 3 in fiscal 2024.
Piotroski F-score, annual
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Annual newest first
| Period | Piotroski F-score | Change (points) |
|---|---|---|
| FY2025 | 2 | (1.00) |
| FY2024 | 3 | 0.00 |
| FY2023 | 3 | 1.00 |
| FY2022 | 2 | (5.00) |
| FY2021 | 7 | 4.00 |
| FY2020 | 3 | 0.00 |
| FY2019 | 3 | (1.00) |
| FY2018 | 4 | (1.00) |
| FY2017 | 5 | 3.00 |
| FY2016 | 2 | — |
How fiscal 2025’s score is made up
| Test | This year | Year before | Result | Points |
|---|---|---|---|---|
| Positive return on assets | (55.86%) | (19.67%) | Fail | 0 |
| Positive operating cash flow | (163.58m) | (150.05m) | Fail | 0 |
| Rising return on assets | (55.86%) | (19.67%) | Fail | 0 |
| Cash flow above net income | 80.51m | (27.74m) | Pass | 1 |
| Falling long-term leverage | 0.00 | 0.00 | Pass | 1 |
| Rising current ratio | 7.72 | 10.01 | Fail | 0 |
| No new shares issued | 53,829,000 | 53,772,000 | Fail | 0 |
| Rising gross margin | 100.00% | 100.00% | Fail | 0 |
| Rising asset turnover | 0.02 | 0.22 | Fail | 0 |
| Piotroski F-score | Weak — most fundamentals deteriorated | 2 | ||
How the Piotroski F-score works
One point for each of nine tests, this fiscal year against the one before: positive return on assets, positive operating cash flow, rising return on assets, cash flow above net income, falling long-term leverage, a rising current ratio, no new shares issued, a rising gross margin and rising asset turnover. The ratios are the ones on this site, so each can be checked.
Joseph Piotroski (2000) called 8–9 high and 0–1 low; reading it in three bands is the common convention:
| 7–9 | Strong — most fundamentals improved |
|---|---|
| 4–6 | Mixed |
| 0–3 | Weak — most fundamentals deteriorated |
Where this differs from the paper: return on assets is on average rather than beginning-of-year assets, and weighted basic shares stand in for shares issued. The score is shown only when all nine tests can be worked out, which takes three fiscal years; banks and insurers, which report no current assets or gross profit, have none.
Piotroski F-score against peers
| Company | Piotroski F-score |
|---|---|
| CAPR Capricor Therapeutics, Inc. compare | 4 |
| ASMB Assembly Biosciences, Inc. compare | 4 |
| PRTA Prothena Corporation plc | 2 |
| EDIT Editas Medicine, Inc. compare | 2 |
| ENTX Entera Bio Ltd. compare | — |
| DMAC DiaMedica Therapeutics, Inc. compare | — |
| TECX Tectonic Therapeutic, Inc. compare | — |
| YDES YD Bio Limited compare | — |
| RZLT Rezolute, Inc. compare | — |
What Piotroski F-score is
The Piotroski F-Score tells an investor how many signs of improving profitability, funding and efficiency a company shows against a year earlier.
One point for each of nine tests against a year earlier: positive return on assets, positive operating cash flow, rising return on assets, cash flow above net income, falling long-term leverage, rising current ratio, no new shares issued, rising gross margin, and rising asset turnover