For the twelve months ended Sep 30, 2026, Prothena Corporation plc reported $52.73M of revenue and -$23.96M of net income.
PRTA revenue was $620.0K in fiscal Q3 2026 (ended Sep 30, 2026), down 74.3% from a year earlier and down 38.6% from the prior quarter. For the full fiscal 2025 it was $9.68M, down 92.8% from fiscal 2024. Compound annual growth was +62.6% over 5 years and +19.7% over 10 years. It rose in 5 of the last 10 fiscal years.
PRTA net income was -$16.51M in fiscal Q3 2026 (ended Sep 30, 2026), compared with -$36.54M a year earlier. For the full fiscal 2025 it was -$244.09M, compared with -$122.31M in fiscal 2024.
PRTA diluted EPS was -$0.32 in fiscal Q3 2026 (ended Sep 30, 2026), compared with -$0.68 a year earlier. For the full fiscal 2025 it was -$4.53, compared with -$2.27 in fiscal 2024.
| Line item | Dec 31, 2025 | Dec 31, 2024 | Dec 31, 2023 | Dec 31, 2022 | Dec 31, 2021 | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 | Dec 31, 2017 | Dec 31, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|
| Revenue | $9.68M | $135.16M | $91.37M | $53.91M | $200.58M | $853.0K | $814.0K | $955.0K | $27.52M | $1.05M |
| Research and development | $134.85M | $222.52M | $220.57M | $135.56M | $82.28M | $74.88M | $50.84M | $101.18M | $134.55M | $119.53M |
| Selling, general and admin | $59.39M | $67.20M | $61.84M | $49.90M | $46.32M | $38.70M | $35.74M | $42.48M | $48.23M | $41.06M |
| Operating income | -$214.64M | -$154.56M | -$191.04M | -$131.56M | $71.97M | -$112.73M | -$85.70M | -$158.85M | -$155.25M | -$159.53M |
| Pre-tax income | -$200.83M | -$128.93M | -$160.48M | -$125.61M | $71.92M | -$111.43M | -$77.30M | -$156.12M | -$157.60M | -$158.96M |
| Income tax | $43.26M | -$6.62M | -$13.45M | -$8.66M | $4.95M | -$283.0K | $379.0K | -$470.0K | -$4.37M | $1.14M |
| Net income | -$244.09M | -$122.31M | -$147.03M | -$116.95M | $66.97M | -$111.14M | -$77.68M | -$155.65M | -$153.24M | -$160.11M |
| EPS, basic | -$4.53 | -$2.27 | -$2.76 | -$2.47 | $1.51 | -$2.78 | -$1.95 | -$3.93 | -$4.07 | -$4.66 |
| EPS, diluted | -$4.53 | -$2.27 | -$2.76 | -$2.47 | $1.38 | -$2.78 | -$1.95 | -$3.93 | -$4.07 | -$4.66 |
| Diluted shares | 53.8M | 53.8M | 53.2M | 47.4M | 48.5M | 39.9M | 39.9M | 39.6M | 37.7M | 34.4M |
| Line item | Dec 31, 2025 | Dec 31, 2024 | Dec 31, 2023 | Dec 31, 2022 | Dec 31, 2021 | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 | Dec 31, 2017 | Dec 31, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|
| Cash and equivalents | $307.53M | $472.25M | $618.83M | $712.62M | $580.45M | $298.08M | $378.43M | $431.71M | $421.68M | $390.98M |
| Receivables | - | $0 | $5.16M | $0 | $0 | $15.0K | $68.0K | $2.0K | $240.0K | $178.0K |
| Current assets | $315.19M | $485.41M | $639.28M | $719.10M | $584.81M | $299.28M | $378.38M | $431.39M | $426.33M | $391.36M |
| Total assets | $326.80M | $547.11M | $696.38M | $758.03M | $609.37M | $332.98M | $419.27M | $498.80M | $496.33M | $459.98M |
| Current liabilities | $40.84M | $48.50M | $56.89M | $50.15M | $33.45M | $25.85M | $17.71M | $14.93M | $37.37M | $41.08M |
| Total liabilities | $46.33M | $60.18M | $135.02M | $135.99M | $143.32M | $148.97M | $146.35M | $175.80M | $89.14M | $94.57M |
| Shareholders' equity | $280.47M | $486.93M | $561.37M | $622.04M | $466.04M | $184.01M | $272.92M | $323.00M | $407.19M | $365.40M |
| Line item | Dec 31, 2025 | Dec 31, 2024 | Dec 31, 2023 | Dec 31, 2022 | Dec 31, 2021 | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 | Dec 31, 2017 | Dec 31, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|
| Operating cash flow | -$163.58M | -$150.05M | -$133.91M | -$108.82M | $92.61M | -$80.36M | -$52.97M | -$28.28M | -$131.18M | -$116.25M |
| Investing cash flow | -$138.0K | -$298.0K | -$2.77M | -$464.0K | -$575.0K | -$196.0K | -$547.0K | -$1.73M | -$3.52M | -$16.64M |
| Financing cash flow | -$139.0K | $1.55M | $45.10M | $241.46M | $190.33M | $215.0K | $228.0K | $40.04M | $165.40M | $153.29M |
| Stock-based compensation | $37.64M | $45.96M | $40.91M | $31.32M | $24.66M | $22.01M | $23.59M | $27.01M | $26.76M | $24.93M |
| Depreciation and amortization | $895.0K | $893.0K | $928.0K | $744.0K | $1.11M | $1.51M | $1.56M | $3.22M | $3.07M | $2.43M |
| Line item | Dec 31, 2025 | Dec 31, 2024 | Dec 31, 2023 | Dec 31, 2022 | Dec 31, 2021 | Dec 31, 2020 | Dec 31, 2019 | Dec 31, 2018 | Dec 31, 2017 | Dec 31, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|
| Revenue growth, YoY | -92.8% | 47.9% | 69.5% | -73.1% | 23414.3% | 4.8% | -14.8% | -96.5% | 2508.4% | -34.3% |
| Operating margin | -2216.4% | -114.4% | -209.1% | -244.1% | 35.9% | -13216.2% | -10527.9% | -16634.0% | -564.2% | -15121.8% |
| Net margin | -2520.6% | -90.5% | -160.9% | -217.0% | 33.4% | -13029.8% | -9542.6% | -16297.9% | -556.8% | -15176.1% |
| Return on equity | -87.0% | -25.1% | -26.2% | -18.8% | 14.4% | -60.4% | -28.5% | -48.2% | -37.6% | -43.8% |
| Return on assets | -74.7% | -22.4% | -21.1% | -15.4% | 11.0% | -33.4% | -18.5% | -31.2% | -30.9% | -34.8% |
| Current ratio | 7.72 | 10.01 | 11.24 | 14.34 | 17.48 | 11.58 | 21.36 | 28.90 | 11.41 | 9.53 |
| Line item | Sep 30, 2026 | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Revenue | $620.0K | $1.01M | $51.08M | $21.0K | $2.42M | $4.42M | $2.83M | $2.12M | $970.0K | $132.01M | $50.0K | $316.0K |
| Research and development | $8.43M | $8.80M | $12.63M | $14.59M | $28.94M | $40.52M | $50.81M | $50.17M | $50.72M | $57.51M | $64.11M | $61.89M |
| Selling, general and admin | $10.59M | $10.90M | $12.67M | $12.65M | $13.24M | $15.91M | $17.60M | $16.85M | $16.76M | $16.13M | $17.46M | $16.94M |
| Operating income | -$18.82M | -$21.10M | $30.04M | -$24.20M | -$40.24M | -$84.62M | -$65.58M | -$64.90M | -$66.51M | $58.38M | -$81.53M | -$78.52M |
| Pre-tax income | -$16.51M | -$18.58M | $32.72M | -$21.58M | -$36.91M | -$80.97M | -$61.37M | -$59.50M | -$59.84M | $64.85M | -$74.44M | -$70.62M |
| Income tax | $2.0K | $2.0K | $1.0K | $10.0K | -$371.0K | $44.80M | -$1.18M | -$1.54M | -$835.0K | -$2.04M | -$2.20M | -$3.14M |
| Net income | -$16.51M | -$18.58M | $32.72M | -$21.59M | -$36.54M | -$125.77M | -$60.20M | -$57.96M | -$59.00M | $66.89M | -$72.24M | -$67.48M |
| EPS, basic | -$0.32 | -$0.36 | $0.61 | -$0.39 | -$0.68 | -$2.34 | -$1.12 | -$1.07 | -$1.10 | $1.24 | -$1.34 | -$1.25 |
| EPS, diluted | -$0.32 | -$0.36 | $0.60 | -$0.39 | -$0.68 | -$2.34 | -$1.12 | -$1.05 | -$1.10 | $1.22 | -$1.34 | -$1.22 |
| Diluted shares | 51.4M | 52.1M | 54.1M | - | 53.8M | 53.8M | 53.8M | - | 53.8M | 55.0M | 53.7M | - |
| Line item | Sep 30, 2026 | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cash and equivalents | $271.37M | $288.19M | $329.46M | $307.53M | $330.84M | $371.44M | $417.94M | $472.25M | $519.26M | $564.12M | $546.51M | $618.83M |
| Receivables | - | - | - | - | - | - | - | $0 | $0 | $0 | $0 | $5.16M |
| Current assets | $273.86M | $292.01M | $339.20M | $315.19M | $339.97M | $385.48M | $436.17M | $485.41M | $534.98M | $585.98M | $565.87M | $639.28M |
| Total assets | $283.52M | $302.58M | $349.89M | $326.80M | $352.63M | $399.07M | $495.34M | $547.11M | $595.25M | $645.57M | $623.19M | $696.38M |
| Current liabilities | $11.43M | $11.66M | $32.52M | $40.84M | $51.44M | $67.81M | $48.46M | $48.50M | $46.42M | $46.74M | $43.27M | $56.89M |
| Total liabilities | $14.68M | $15.69M | $37.28M | $46.33M | $57.64M | $74.73M | $57.66M | $60.18M | $60.89M | $63.65M | $120.80M | $135.02M |
| Shareholders' equity | $268.84M | $286.89M | $312.62M | $280.47M | $294.99M | $324.33M | $437.68M | $486.93M | $534.36M | $581.92M | $502.40M | $561.37M |
| Line item | Sep 30, 2026 | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating cash flow | -$11.96M | -$25.05M | $28.88M | -$23.31M | -$40.56M | -$46.34M | -$53.36M | -$47.77M | -$45.19M | $15.96M | -$73.05M | -$51.04M |
| Investing cash flow | -$73.0K | -$652.0K | $0 | $0 | -$10.0K | -$86.0K | -$42.0K | -$43.0K | -$9.0K | -$143.0K | -$103.0K | -$1.51M |
| Financing cash flow | -$4.79M | -$15.57M | -$6.95M | $0 | -$17.0K | -$74.0K | -$48.0K | -$59.0K | $333.0K | $444.0K | $836.0K | $483.0K |
| Stock-based compensation | $6.41M | $7.88M | $6.92M | $7.07M | $7.20M | $12.42M | $10.95M | $10.52M | $11.02M | $12.04M | $12.38M | $11.08M |
| Depreciation and amortization | $209.0K | $197.0K | $184.0K | $218.0K | $229.0K | $225.0K | $223.0K | $221.0K | $226.0K | $231.0K | $215.0K | $276.0K |
| Line item | Sep 30, 2026 | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Revenue growth, YoY | -74.3% | -77.1% | 1706.4% | -99.0% | 149.0% | -96.7% | 5556.0% | 571.8% | -98.9% | 3184.7% | -97.7% | -99.4% |
| Operating margin | -3035.6% | -2089.2% | 58.8% | -115252.4% | -1666.3% | -1914.4% | -2319.0% | -3056.9% | -6857.0% | 44.2% | -163056.0% | -24846.5% |
| Net margin | -2662.7% | -1839.9% | 64.1% | -102804.8% | -1513.1% | -2845.4% | -2128.5% | -2729.9% | -6082.6% | 50.7% | -144478.0% | -21353.2% |
| Current ratio | 23.95 | 25.05 | 10.43 | 7.72 | 6.61 | 5.68 | 9.00 | 10.01 | 11.52 | 12.54 | 13.08 | 11.24 |
Source: XBRL data Prothena Corporation plc files with the SEC, latest filing dated Nov 5, 2026 (see filings on SEC EDGAR). Provided for information only, not investment advice. Check the filing before relying on a number.
* Worked out from the filings rather than stated in them: Q4 is the full year less the first nine months.
Per-share figures are as filed. The filings show no stock split in these periods.
EPS growth is left out where the share count moved enough to suggest a split the filings do not show. Growth rates need a positive starting figure. CAGR is compound annual growth between fiscal years. The CSV holds every period on file, in full figures, from the same SEC filings.
| Company | Revenue | Growth | Net income | Net margin | Market cap |
|---|---|---|---|---|---|
| PRTA | $52.73M | +347.4% | -$23.96M | -45.4% | $450.9M |
| LLY | $86.46B | +45.5% | $27.58B | 31.9% | $1.33T |
| JNJ | $99.33B | +7.8% | $16.09B | 16.2% | $679.13B |
| ABBV | $66.01B | +10.7% | $10.34B | 15.7% | $518.44B |
| MRK | $67.38B | +4.9% | $2.45B | 3.6% | $366.73B |
| NVS | $54.53B | +8.4% | $13.98B | 25.6% | $312.35B |
| AZN | $58.74B | +8.6% | $10.22B | 17.4% | $293.69B |
| ABT | $48.23B | +10.0% | $4.70B | 9.7% | $191.40B |
| NVO | DKK 309.06B | +6.4% | DKK 102.43B | 33.1% | $183.23B |