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) Altman Z-score
Prothena Corporation plc's Altman Z-score for fiscal 2025 is −0.24, in the distress zone (below 1.81).
Altman Z-score, annual
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Annual newest first
| Period | Altman Z-score | Change (points) |
|---|---|---|
| FY2025 | −0.24 | (5.12) |
| FY2024 | 4.88 | (1.98) |
| FY2023 | 6.85 | (4.76) |
| FY2022 | 11.61 | 2.30 |
| FY2021 | 9.31 | 10.80 |
| FY2020 | −1.49 | (2.20) |
| FY2019 | 0.70 | 1.04 |
| FY2018 | −0.33 | (8.55) |
| FY2017 | 8.22 | (1.39) |
| FY2016 | 9.61 | (40.79) |
How fiscal 2025’s score is made up
| Component | This year | Year before | Result | Points |
|---|---|---|---|---|
| Working capital / total assets | 0.84 | — | 1.01 | |
| Retained earnings / total assets | (4.12) | — | −5.77 | |
| EBIT / total assets | (0.66) | — | −2.17 | |
| Market value of equity / total liabilities | 11.10 | — | 6.66 | |
| Sales / total assets | 0.03 | — | 0.03 | |
| Altman Z-score | Distress zone | −0.24 | ||
| Z″ Variant for non-manufacturing and asset-light companies (drops the sales/assets term, uses book equity) | Distress zone | −5.98 | ||
How the Altman Z-score works
Z = 1.2 × working capital ÷ total assets + 1.4 × retained earnings ÷ total assets + 3.3 × EBIT ÷ total assets + 0.6 × market value of equity ÷ total liabilities + 1.0 × revenue ÷ total assets (Altman, 1968). The market value of equity is the close on the last trading day of the fiscal year times weighted basic shares.
Z″ = 6.56 × working capital ÷ total assets + 3.26 × retained earnings ÷ total assets + 6.72 × EBIT ÷ total assets + 1.05 × book equity ÷ total liabilities (Altman, Hartzell and Peck, 1995), the variant for non-manufacturing and asset-light companies.
| Zone | Z | Z″ |
|---|---|---|
| Safe zone | above 2.99 | above 2.60 |
| Grey zone | 1.81–2.99 | 1.10–2.60 |
| Distress zone | below 1.81 | below 1.10 |
Not worked out for banks, insurers and REITs, whose balance sheets the model does not describe, nor when a figure is missing or there is no share price in the week to the fiscal year end.
Altman Z-score against peers
| Company | Altman Z-score |
|---|---|
| CAPR Capricor Therapeutics, Inc. compare | 10.3× |
| DMAC DiaMedica Therapeutics, Inc. compare | 6.7× |
| ENTX Entera Bio Ltd. compare | 6.2× |
| ASMB Assembly Biosciences, Inc. compare | 1.1× |
| PRTA Prothena Corporation plc | −0.2× |
| EDIT Editas Medicine, Inc. compare | −13.4× |
| TECX Tectonic Therapeutic, Inc. compare | — |
| YDES YD Bio Limited compare | — |
| RZLT Rezolute, Inc. compare | — |
What Altman Z-score is
The Altman Z-Score weighs working capital, retained earnings, operating profit, market value and sales against assets and debts to gauge the risk of distress.
1.2 × working capital ÷ total assets + 1.4 × retained earnings ÷ total assets + 3.3 × EBIT ÷ total assets + 0.6 × market value of equity ÷ total liabilities + 1.0 × revenue ÷ total assets