Prothena Corporation plc (PRTA) Cash Flow Statement
Where PRTA’s cash came from and went, 2025
December 31, 2025 · U.S. dollars- Cash from operations
- −$163.6M
- Capital expenditures
- $138,000 1.4% of revenue
- Free cash flow
- −$163.7M −1,690.6% margin
- Returned to shareholders
- $139,000
- Change in cash
- −$163.9M cash at year-end $308.4M
Drawn to scale: where the cash came from and how it was used. Hover for values.
PRTA operating cash flow, capex and free cash flow
PRTA cash flow trends, 2016–2025
| Metric | Trend | Then | Latest | Change |
|---|---|---|---|---|
| Operating cash flow | −$117.3M2016 | −$163.6M2025 | — | |
| Capital expenditures | $16.6M2016 | $138,0002025 | −41.3%/yr | |
| Free cash flow | −$133.9M2016 | −$163.7M2025 | — | |
| Free cash flow margin | −12,693.2%2016 | −1,690.6%2025 | +11,002.6 pts | |
| Stock-based compensation | $24.9M2016 | $37.6M2025 | +4.7%/yr | |
| Dividends paid | $02016 | $02017 | — | |
| Share buybacks (net) | $02016 | $139,0002025 | — | |
| Capex / revenue | 1,577.6%2016 | 1.4%2025 | −1,576.2 pts |
Change is the average annual growth (CAGR) or the difference between the first and latest year.
PRTA cash flow by activity
PRTA net income vs operating cash flow
Operating cash flow above net income usually means earnings are backed by cash (depreciation and stock-based pay are non-cash expenses).
PRTA cash flow statement
| 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Operating activities | ||||||||||
| Net income | −$244.1M | −$122.3M | −$147.0M | −$116.9M | $67.0M | −$111.1M | −$77.7M | −$155.6M | −$153.2M | −$160.1M |
| Depreciation & amortization | $895,000 | $893,000 | $928,000 | $744,000 | $1.1M | $1.5M | $6.8M | $3.2M | $3.1M | $2.4M |
| Stock-based compensation | $37.6M | $46.0M | $40.9M | $31.3M | $24.7M | $22.0M | $23.6M | $27.0M | $26.8M | $24.9M |
| Change in working capital | −$4.2M | −$67.9M | −$20.5M | −$18.8M | −$10.4M | $3.5M | −$4.4M | $94.5M | −$7.2M | $18.9M |
| Other non-cash items | $46.1M | −$6.7M | −$8.2M | −$5.1M | $10.3M | $3.8M | −$1.2M | $2.7M | −$613,000 | −$3.4M |
| Cash from operating activities | −$163.6M | −$150.1M | −$133.9M | −$108.8M | $92.6M | −$80.4M | −$53.0M | −$28.3M | −$131.2M | −$117.3M |
| Investing activities | ||||||||||
| Capital expenditures | −$138,000 | −$298,000 | −$2.8M | −$464,000 | −$575,000 | −$196,000 | −$555,000 | −$1.8M | −$3.6M | −$16.6M |
| Investments (net) | — | −$298,000 | −$1.4M | −$464,000 | −$575,000 | −$196,000 | −$547,000 | −$1.7M | −$3.5M | −$16.6M |
| Acquisitions & other investing | $0 | $298,000 | $1.4M | $464,000 | $575,000 | $196,000 | $555,000 | $1.8M | $3.6M | $16.6M |
| Cash from investing activities | −$138,000 | −$298,000 | −$2.8M | −$464,000 | −$575,000 | −$196,000 | −$547,000 | −$1.7M | −$3.5M | −$16.6M |
| Financing activities | ||||||||||
| Dividends paid | — | — | — | — | — | — | — | — | $0 | $0 |
| Share repurchases & issuance (net) | −$139,000 | −$353,000 | — | — | $93.6M | $215,000 | $228,000 | $44.4M | $168.2M | $139.3M |
| Net borrowing (repayment) | — | — | — | — | — | — | — | −$4.4M | −$2.8M | −$169,000 |
| Shares issued | $0 | $0 | $232.8M | $223.6M | $174.8M | $78.4M | $0 | $39.8M | $0 | $0 |
| Other financing | $0 | $1.9M | −$187.7M | $17.8M | −$78.0M | −$78.4M | $0 | −$39.8M | $0 | $15.2M |
| Cash from financing activities | −$139,000 | $1.6M | $45.1M | $241.5M | $190.3M | $215,000 | $228,000 | $40.0M | $165.4M | $154.3M |
| Summary | ||||||||||
| Net change in cash | −$163.9M | −$148.8M | −$91.6M | $132.2M | $282.4M | −$80.3M | −$53.3M | $10.0M | $30.7M | $20.4M |
| Cash at end of period | $308.4M | $472.2M | $621.0M | $712.6M | $580.4M | $298.1M | $378.4M | $431.7M | $421.7M | $391.0M |
| Free cash flow | −$163.7M | −$150.3M | −$136.7M | −$109.3M | $92.0M | −$80.6M | −$53.5M | −$30.0M | −$134.8M | −$133.9M |
| Free cash flow margin | −1,690.6% | −111.2% | −149.6% | −202.7% | 45.9% | −9,444.1% | −6,575.4% | −3,146.0% | −489.9% | −12,693.2% |
| Capex / revenue | 1.4% | 0.2% | 3.1% | 0.9% | 0.3% | 23.0% | 68.2% | 185.1% | 13.2% | 1,577.6% |
| Operating cash flow / net income | — | — | — | — | 1.38 | — | — | — | — | — |
| Jun '26 | Mar '26 | Dec '25 | Sep '25 | Jun '25 | Mar '25 | Dec '24 | Sep '24 | Jun '24 | Mar '24 | Dec '23 | Sep '23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating activities | ||||||||||||
| Net income | −$18.6M | $32.7M | −$21.6M | −$36.5M | −$125.8M | −$60.2M | −$58.0M | −$59.0M | $66.9M | −$72.2M | −$67.5M | $21.9M |
| Depreciation & amortization | $197,000 | $184,000 | $218,000 | $229,000 | $225,000 | $223,000 | $221,000 | $226,000 | $231,000 | $215,000 | $14.3M | $229,000 |
| Stock-based compensation | $7.9M | $6.9M | $7.1M | $7.2M | $12.4M | $10.9M | $10.5M | $11.0M | $12.0M | $12.4M | $11.1M | $10.9M |
| Change in working capital | −$13.5M | −$6.5M | −$9.8M | −$12.2M | $21.2M | −$3.4M | $988,000 | $5.6M | −$61.1M | −$11.3M | $6.8M | −$21.7M |
| Other non-cash items | −$1.0M | −$4.5M | $825,000 | $715,000 | $45.6M | −$984,000 | −$1.5M | −$3.0M | −$2.1M | −$2.1M | −$15.7M | −$1.9M |
| Cash from operating activities | −$25.0M | $28.9M | −$23.3M | −$40.6M | −$46.3M | −$53.4M | −$47.8M | −$45.2M | $16.0M | −$73.1M | −$51.0M | $9.5M |
| Investing activities | ||||||||||||
| Capital expenditures | −$652,000 | $0 | −$2,040 | −$10,000 | −$86,000 | −$42,000 | −$43,000 | −$9,000 | −$143,000 | −$103,000 | −$1.5M | −$442,000 |
| Investments (net) | — | — | — | −$10,000 | −$86,000 | −$42,000 | −$43,000 | −$9,000 | −$143,000 | −$103,000 | −$1.5M | −$442,000 |
| Acquisitions & other investing | $0 | — | $4,076 | $10,000 | $86,000 | $42,000 | $43,000 | $9,000 | $143,000 | $103,000 | $1.5M | $442,000 |
| Cash from investing activities | −$652,000 | — | $2,036 | −$10,000 | −$86,000 | −$42,000 | −$43,000 | −$9,000 | −$143,000 | −$103,000 | −$1.5M | −$442,000 |
| Financing activities | ||||||||||||
| Share repurchases & issuance (net) | −$15.6M | −$6.9M | −$170,000 | −$17,000 | −$74,000 | −$48,000 | −$58,000 | −$94,000 | −$147,000 | −$54,000 | — | — |
| Shares issued | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 |
| Other financing | $0 | $0 | $172,051 | $0 | $0 | $0 | −$1,000 | $427,000 | $591,000 | $890,000 | $483,000 | $2.7M |
| Cash from financing activities | −$15.6M | −$6.9M | $2,051 | −$17,000 | −$74,000 | −$48,000 | −$59,000 | $333,000 | $444,000 | $836,000 | $483,000 | $2.7M |
| Summary | ||||||||||||
| Net change in cash | −$41.3M | $21.9M | −$23.3M | −$40.6M | −$46.5M | −$53.5M | −$47.9M | −$44.9M | $16.3M | −$72.3M | −$52.1M | $11.8M |
| Cash at end of period | $289.1M | $330.3M | $308.4M | $331.7M | $372.3M | $418.8M | $472.2M | $520.1M | $565.0M | $548.7M | $621.0M | $673.1M |
| Free cash flow | −$25.7M | $28.9M | −$23.3M | −$40.6M | −$46.4M | −$53.4M | −$47.8M | −$45.2M | $15.8M | −$73.2M | −$52.6M | $9.1M |
| Free cash flow margin | −2,544.7% | 56.5% | −111,009.5% | −1,680.1% | −1,050.4% | −1,888.4% | −2,252.2% | −4,659.3% | 12.0% | −146,308.0% | −16,641.5% | 10.7% |
| Capex / revenue | 64.6% | 0.0% | 9.7% | 0.4% | 1.9% | 1.5% | 2.0% | 0.9% | 0.1% | 206.0% | 490.2% | 0.5% |
| Operating cash flow / net income | — | 0.88 | — | — | — | — | — | — | 0.24 | — | — | 0.43 |
Negative numbers are cash paid out. Quarterly columns are labeled by the month the quarter ended. Figures in U.S. dollars as reported; data from EODHD.
PRTA cash generation
In fiscal 2025 (ended December 31, 2025), Prothena generated -$163.6 million of cash from operations and spent $0.1 million on capital expenditures, leaving free cash flow of -$163.7 million, −1,690.6% of revenue. It returned $0.1 million to shareholders through dividends ($0) and net share buybacks ($0.1 million). Cash and equivalents fell by $163.9 million over the year.
Related: PRTA income statement, PRTA balance sheet. See the PRTA stock overview for the latest quote and news.
PRTA cash flow FAQ
What is Prothena's free cash flow?
Prothena's free cash flow was -$163.7 million in fiscal 2025: -$163.6 million of operating cash flow minus $0.1 million of capital expenditures It was -$150.3 million a year earlier..
How much cash does Prothena generate from operations?
Prothena generated -$163.6 million of cash from operating activities in fiscal 2025.
How much does Prothena spend on capital expenditures?
Prothena spent $0.1 million on capital expenditures in fiscal 2025, 1.4% of revenue, compared with $0.3 million the year before.
How much stock does Prothena buy back?
Prothena spent $0.1 million on net share repurchases in fiscal 2025.