Pricing Log in Create free account
Tuesday 13 October 2026 Export PRTA’s income statement to Excel — free account

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.

8.48 0.05 +0.59%
Market cap
$432.8M
P/E
0.0×
Fwd P/E
188×
Dividend yield
—
F-score
2/9
Altman Z
−0.24
Beneish M
n/a
Dividend safety
n/a
Overview Business Profile Financial Analysis Income Statement Balance Sheet Cash Flow Metrics & Ratios 10-Q 10-K

Insider Decisions trades per month

Total buys 9.93
Total sells 0.14
Totals in millions of $.
Dec 25 Mar 26 Jun 26 Sep 26
Buy — — — — — — 1 4 — 2 4 2
Sell — — — — — — — — 2 — — —
Insider Ownership 15.16%

Capital & Financial Ratios $m

Market Cap 432.77
Revenue 54.53
Net Income (43.99)
Free Cash Flow (60.80)
Net Debt (288.19)
Current Ratio 25.05 (at or above 1.5: strong)
Debt/Equity 0.00 (at or below 0.5: strong)
P/E ratio 0.00
Fwd P/E 188.00 (above 35: high)
P/S ratio 8.06
P/B ratio 1.53
Past 5Y EPS Growth —
This Y EPS Growth 102.43% (at or above 15%: strong)
Next Y EPS Growth (943.94%) (below 0%: weak)
Next Y revenue growth 758.74% (at or above 10%: strong)
Next 5Y EPS Growth 61.68% (at or above 15%: strong)

Green and red mark values outside typical ranges. How we judge →

Valuation vs history

EV/Sales, ten years
EV/Sales is 2.8×, against a ten-year median of 33.4×; over the ten years it ranged from −103× in 2019 to 1,543× in 2017.
P/S against its own 10 years 13.22%
10-year low 10-year high
P/B against its own 10 years 19.34%
10-year low 10-year high
EV/Sales against its own 10 years 7.87%
10-year low 10-year high

Dividends

Payout Ratio —
Annual Dividend Rate —
Annual Dividend Yield —
total individual payouts
2025 Powerpack
2024 Powerpack
2023 Powerpack
2022 Powerpack
2021 Powerpack
2020 Powerpack
2019 Powerpack
2017 Powerpack
predictions special payouts not included in total or ratios

Assets vs Liabilities $m

2023 2024 2025 Q'26
Cash 620 471 308 288
Receivables 5 — — —
Inventory — — — —
Other — — — —
639 485 315 292
2023 2024 2025 Q'26
Payables 25 8 6 2
ST’ Debt — — — —
Other 16 16 25 6
57 49 41 12

Compound Annual Growth %

10y 5y 3y
Sales 19.68% 62.56% (43.57%)
Cash Flow 0.00% 0.00% 0.00%
Earnings 0.00% 0.00% 0.00%
Book Value (2.48%) 8.80% (23.32%)

Revenue $m

Mar Jun Sep Dec Year
’26 51 1 — — —
’25 3 4 2 0 10
’24 0 132 1 2 135
’23 2 4 85 0 91
’22 1 1 2 50 54
’21 0 60 139 1 201
’20 0 0 0 0 1
Fiscal quarters ending in the months shown.

Operating Cash Flow $m

Mar Jun Sep Dec Year
’26 29 (25) — — —
’25 (53) (46) (41) (23) (164)
’24 (73) 16 (45) (48) (150)
’23 (47) (45) 10 (51) (134)
’22 (37) (35) (31) (5) (109)
’21 (34) 37 112 (22) 93
’20 (23) (19) (19) (19) (80)
Fiscal quarters ending in the months shown.

Free Cash Flow $m

Mar Jun Sep Dec Year
’26 29 (26) — — —
’25 (53) (46) (41) (23) (164)
’24 (73) 16 (45) (48) (150)
’23 (48) (46) 9 (53) (137)
’22 (37) (35) (31) (5) (109)
’21 (34) 37 112 (23) 92
’20 (23) (19) (19) (19) (81)
Fiscal quarters ending in the months shown.

EPS $

Mar Jun Sep Dec Year
’26 0.60 (0.36) — — —
’25 (1.12) (2.34) (0.68) (0.40) (4.53)
’24 (1.34) 1.22 (1.10) (1.08) (2.27)
’23 (0.89) (1.03) 0.38 (1.26) (2.76)
’22 (0.78) (0.88) (0.97) 0.12 (2.47)
’21 (0.91) 0.58 2.13 (0.71) 1.38
’20 (0.59) (0.66) (0.77) (0.77) (2.78)
Fiscal quarters ending in the months shown.

Target Price Range

Analyst price targets

Recommendation Rating

2.2
1Buy 2 3Hold 4 5Sell

Ten years at a glance Fiscal years to December

Group Line 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Trend 2026e 2027e 2028e
Price, $
Price, $ Low 28.20 34.85 8.63 6.71 7.10 10.72 21.06 28.51 11.70 4.32

Analyst estimates 2026–2028

Powerpack
High 68.18 70.00 46.14 17.63 16.05 79.75 66.47 79.65 41.55 16.67
People
People Employees 96 125 59 51 66 82 127 173 163 67
Revenue/emp, $m 0.01 0.22 0.02 0.02 0.01 2.45 0.42 0.53 0.83 0.14
Income, $m
Income, $m Revenue 1 28 1 1 1 201 54 91 135 10
Gross margin, % 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
EBT (159) (158) (156) (77) (111) 72 (126) (160) (129) (201)
EBT margin, % (15,067.68) (572.71) (16,347.12) (9,496.07) (13,062.95) 35.86 (233.01) (175.64) (95.39) (2,073.82)
Net income (160) (153) (156) (78) (111) 67 (117) (147) (122) (244)
Depreciation 2 3 3 7 7 7 7 8 4 4
Per share, $
Per share, $ Revenue 0.03 0.73 0.02 0.02 0.02 4.54 1.14 1.72 2.51 0.18
Earnings (4.66) (4.07) (3.93) (1.95) (2.78) 1.51 (2.47) (2.76) (2.27) (4.53)
Cash flow (3.38) (3.48) (0.71) (1.33) (2.01) 2.09 (2.30) (2.52) (2.79) (3.04)
Capex (0.48) (0.09) (0.04) (0.01) 0.00 (0.01) (0.01) (0.05) (0.01) 0.00
Free cash flow (3.87) (3.58) (0.76) (1.34) (2.02) 2.08 (2.31) (2.57) (2.80) (3.04)
Book value 10.64 10.81 8.17 6.84 4.61 10.54 13.13 10.55 9.06 5.21
Shares, m 34 38 40 40 40 44 47 53 54 54
Valuation, ×
Valuation, × P/E 0.00 0.00 0.00 0.00 0.00 35.54 0.00 0.00 0.00 0.00
P/S 1,621.17 51.72 426.66 775.59 561.99 10.89 47.01 22.45 5.51 53.08
P/B 4.68 3.50 1.26 2.31 2.61 4.69 4.07 3.65 1.53 1.83
EV/Sales 1,254.42 36.55 (21.15) 314.02 214.12 8.01 33.83 15.66 2.02 21.33
EV/FCF (9.96) (7.47) 0.67 (4.78) (2.27) 17.45 (16.69) (10.47) (1.82) (1.26)
Cash, $m
Cash, $m Operating cash flow (116) (131) (28) (53) (80) 93 (109) (134) (150) (164)
Capex (17) (4) (2) (1) 0 (1) 0 (3) 0 0
Free cash flow (133) (135) (30) (54) (81) 92 (109) (137) (150) (164)
Balance, $m
Balance, $m Working capital 350 389 416 361 273 551 669 582 437 274
Total debt — — — 23 18 12 6 — — —
Net debt (387) (418) (428) (376) (297) (579) (710) (620) (471) (308)
Shareholders’ equity 365 407 323 273 184 466 622 561 487 280
Returns, %
Returns, % ROA (37.89) (32.05) (31.28) (16.92) (29.55) 14.21 (17.11) (20.22) (19.67) (55.86)
ROIC 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (621.71) 0.00
ROE (44.10) (39.67) (42.63) (26.07) (48.65) 20.61 (21.50) (24.85) (23.34) (63.62)
Negative figures in brackets.

All 10 years →

Fiscal years to Dec 2025 · latest quarter Jun 2026

Charts ten years each

Prothena Corporation plc vs peers in Biotechnology (Q) = latest quarter vs a year earlier

Company Market cap P/E Fwd P/E Revenue growth (Q) EPS growth (Q) FCF growth (Q) Gross margin (Q) EBIT margin (Q) Compare
ASMB Assembly Biosciences, Inc. $479.1M 22.3× — (loss-making) +38.94% (above 0%: growing) n/m +7.58% (above 0%: growing) 100.00% (47.44%) Compare
YDES YD Bio Limited $476.8M — — — — — — — Compare
RZLT Rezolute, Inc. $471.1M — (loss-making) — — n/m +40.23% (above 0%: growing) 0.00% 0.00% Compare
ENTX Entera Bio Ltd. $462.4M — (loss-making) — (loss-making) +200.00% (above 0%: growing) n/m −108.86% (below 0%: shrinking) 0.00% 0.00% Compare
TECX Tectonic Therapeutic, Inc. $456.1M — (loss-making) — — n/m −46.69% (below 0%: shrinking) 0.00% 0.00% Compare
CAPR Capricor Therapeutics, Inc. $455.2M — (loss-making) — (loss-making) −7.92% (below 0%: shrinking) n/m −72.88% (below 0%: shrinking) 100.00% 0.00% Compare
PRTA Prothena Corporation plc $453.8M — (loss-making) 188× −77.15% (below 0%: shrinking) n/m +44.64% (above 0%: growing) 100.00% (2,089.21%)
DMAC DiaMedica Therapeutics, Inc. $449.2M — (loss-making) — (loss-making) — n/m −6.75% (below 0%: shrinking) 0.00% 0.00% Compare
EDIT Editas Medicine, Inc. $445.4M — (loss-making) — (loss-making) +232.31% (above 0%: growing) n/m +40.72% (above 0%: growing) 100.00% (156.05%) Compare
Median of peers $459.2M — — +119.47% — −6.75% 0.00% 0.00%

All 614 Biotechnology stocks →

Prothena Corporation plc (PRTA) key facts

  • Concern: Prothena Corporation plc’s revenue for fiscal 2025 (year ended December 2025) was $9.7 million, down 92.8% from fiscal 2024.
  • Concern: Prothena Corporation plc reported a net loss of $244.1 million, or a loss of $4.53 per share, for fiscal 2025.
  • Prothena Corporation plc (PRTA) is a Biotechnology company in the Healthcare sector, listed on Nasdaq.
  • As of October 13, 2026, PRTA traded at $8.42, a market capitalization of $432.8 million.
  • Trailing earnings are negative, so a P/E ratio is not meaningful; the stock trades at 8.1× sales.
  • Return on equity was −63.6% and debt-to-equity 0.00.
  • Its Piotroski F-score is 2 out of 9 and its Altman Z-score is −0.24 (distress zone) for fiscal 2025.

Source: company filings (standardised) and stockrow calculations.

Prothena Corporation plc (PRTA) Latest News

No news at this impact. Lower the threshold for more.
stockrow.com/PRTA · Data as of Jun 30, 2026 · For information only; not investment advice. · © 2026 stockrow.com