Tuesday 13 October 2026 Export PRTA’s income statement to Excel — free account

Prothena Corporation plc

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%

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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

Debt/Equity 0.00

P/E ratio 0.00

Fwd P/E 188.00

P/S ratio 8.06

P/B ratio 1.53

Past 5Y EPS Growth —

This Y EPS Growth 102.43%

Next Y EPS Growth (943.94%)

Next Y revenue growth 758.74%

Next 5Y EPS Growth 61.68%

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

Valuation vs history

EV/Sales, ten years

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.

Group	Line	2016	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026e
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

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.