PRTA

MKT CAP:$577M

Prothena Corporation plc

Market Cap

$577M

Healthcare·Biotechnology·🇮🇪 Ireland·NASDAQ

Healthcare·Biotechnology·🇮🇪·NASDAQ

Stock Price

$10.73+$1.53 (+16.63%)

Apr 23, 2026

Company Details

Prothena Corporation plc, a late-stage clinical company, focuses on discovery and development of novel therapies for life-threatening diseases in the United States. The company is involved in developing Birtamimab, an investigational humani...

CEO

Gene G. Kinney

IPO Date

Dec 18, 2012

Website

www.prothena.com

Key Metrics TTM

Revenue

$10M

-92.8% YoY

Net Income

-$244M

EPS (Diluted)

-$4.54

Free Cash Flow

-$168M

Revenue / Share

$0.18

Gross Margin

-208.6%

Operating Margin

-2247.5%

Net Margin

-2520.6%

FCF Margin

-1730.4%

P/S

59.6x

P/E

—

Earnings Reports

Q1 2026

May 14, 2026

PENDING

Q4 2025

Feb 27, 2026

$21.0K-99.0%EPS -$0.40

Q3 2025

Nov 6, 2025

$2M+149.0%EPS -$0.68

Q2 2025

Aug 4, 2025

$4M-96.7%EPS -$2.34

Q1 2025

May 8, 2025

$3M+5556.0%EPS -$1.12

Revenue & Profitability

Quarter	Revenue	Gross Profit	Operating Income
Q1 22	$1M	-$26M	-$38M
Q2 22	$1M	-$30M	-$43M
Q3 22	$2M	-$38M	-$50M
Q4 22	$50M	$13M	-$72.0K
Q1 23	$2M	-$43M	-$56M
Q2 23	$4M	-$52M	-$67M
Q3 23	$85M	$27M	$10M
Q4 23	$316.0K	-$62M	-$79M
Q1 24	$50.0K	$50.0K	-$82M
Q2 24	$132M	$132M	$58M
Q3 24	$970.0K	$970.0K	-$67M
Q4 24	$2M	$2M	-$65M
Q1 25	$3M	$3M	-$66M
Q2 25	$4M	$4M	-$85M
Q3 25	$2M	-$27M	-$40M
Q4 25	$21.0K	-$921.0K	-$27M

Valuation

Quarter	P/S	P/E
Q1 22	8.5x	25.5x
Q2 22	9.0x	—
Q3 22	587.3x	—
Q4 22	51.1x	—
Q1 23	47.1x	—
Q2 23	63.9x	—
Q3 23	17.7x	—
Q4 23	20.7x	—
Q1 24	15.7x	—
Q2 24	5.1x	—
Q3 24	6.7x	—
Q4 24	5.9x	—
Q1 25	4.8x	—
Q2 25	31.6x	—
Q3 25	44.6x	—
Q4 25	52.7x	—

Operating Cash Flow

Quarter	Operating CF	Free CF
Q1 22	-$37M	-$37M
Q2 22	-$35M	-$35M
Q3 22	-$31M	-$31M
Q4 22	-$5M	-$5M
Q1 23	-$47M	-$48M
Q2 23	-$45M	-$46M
Q3 23	$10M	$9M
Q4 23	-$51M	-$53M
Q1 24	-$73M	-$73M
Q2 24	$16M	$16M
Q3 24	-$45M	-$45M
Q4 24	-$48M	-$48M
Q1 25	-$53M	-$53M
Q2 25	-$46M	-$46M
Q3 25	-$41M	-$41M
Q4 25	-$27M	-$27M

Capital Expenditures

Quarter	CapEx
Q1 22	$22.0K
Q2 22	$161.0K
Q3 22	$130.0K
Q4 22	$151.0K
Q1 23	$48.0K
Q2 23	$771.0K
Q3 23	$442.0K
Q4 23	$2M
Q1 24	$103.0K
Q2 24	$143.0K
Q3 24	$9.0K
Q4 24	$43.0K
Q1 25	$42.0K
Q2 25	$86.0K
Q3 25	$10.0K
Q4 25	$4.9K

CapEx

OpEx vs Revenue Growth (YoY)

Quarter	Revenue Growth	OpEx Growth
Q1 22	+620.6%	+21.2%
Q2 22	-97.8%	+38.6%
Q3 22	-98.9%	+73.1%
Q4 22	+4159.6%	+45.9%
Q1 23	+88.1%	+49.6%
Q2 23	+206.3%	+58.4%
Q3 23	+5494.3%	+43.8%
Q4 23	-99.4%	+57.7%
Q1 24	-97.7%	+39.5%
Q2 24	+3184.7%	+4.4%
Q3 24	-98.9%	-9.5%
Q4 24	+571.8%	-15.0%
Q1 25	+5556.0%	-16.1%
Q2 25	-96.7%	+20.9%
Q3 25	+149.0%	-36.8%
Q4 25	-99.0%	-59.4%

Stock-Based Compensation

Quarter	SBC ($)	% of Revenue
Q1 22	$8M	664.4%
Q2 22	$8M	629.8%
Q3 22	$8M	525.1%
Q4 22	$7M	14.9%
Q1 23	$9M	405.3%
Q2 23	$10M	251.3%
Q3 23	$11M	12.9%
Q4 23	$11M	3506.3%
Q1 24	$12M	24766.0%
Q2 24	$12M	9.1%
Q3 24	$11M	1136.1%
Q4 24	$11M	495.5%
Q1 25	$11M	387.2%
Q2 25	$12M	281.0%
Q3 25	$7M	298.1%
Q4 25	$7M	33685.7%

OpEx Breakdown

Quarter	R&D	G&A
Q1 22	$27M	$12M
Q2 22	$32M	$13M
Q3 22	$40M	$12M
Q4 22	$37M	$13M
Q1 23	$45M	$14M
Q2 23	$56M	$15M
Q3 23	$58M	$17M
Q4 23	$62M	$17M
Q1 24	$64M	$17M
Q2 24	$58M	$16M
Q3 24	$51M	$17M
Q4 24	$50M	$17M
Q1 25	$51M	$18M
Q2 25	$41M	$16M
Q3 25	$29M	$13M
Q4 25	$15M	$13M

Revenue Segments

Quarter	Collaboration	License
Q4 22	$10M	$40M
Q4 23	$316.0K	—
Q1 24	—	$50.0K
Q2 24	$132M	—
Q3 24	$970.0K	—
Q1 25	$3M	$50.0K
Q2 25	$4M	—
Q3 25	$2M	—
Q4 25	$21.0K	—

War Chest

Quarter	Cash	Short-term Investments	Total
Q1 22	$543M	$0	$543M
Q2 22	$509M	$0	$509M
Q3 22	$496M	$0	$496M
Q4 22	$710M	$0	$710M
Q1 23	$686M	$0	$686M
Q2 23	$659M	$0	$659M
Q3 23	$671M	$0	$671M
Q4 23	$619M	$0	$619M
Q1 24	$547M	$0	$547M
Q2 24	$564M	$0	$564M
Q3 24	$519M	$0	$519M
Q4 24	$471M	$0	$471M
Q1 25	$418M	$0	$418M
Q2 25	$371M	$0	$371M
Q3 25	$331M	$0	$331M
Q4 25	$308M	$0	$308M

Shares Outstanding

Quarter	Shares (Diluted)	QoQ Change	YoY Change
Q1 22	47M	+0.2%	+16.0%
Q2 22	47M	+0.2%	-1.3%
Q3 22	47M	+0.4%	-8.2%
Q4 22	54M	+14.9%	+15.8%
Q1 23	53M	-2.7%	+12.4%
Q2 23	53M	+1.2%	+13.5%
Q3 23	58M	+9.2%	+23.4%
Q4 23	54M	-7.5%	-0.6%
Q1 24	54M	+0.1%	+2.3%
Q2 24	55M	+2.5%	+3.6%
Q3 24	54M	-2.3%	-7.3%
Q4 24	54M	+0.0%	+0.3%
Q1 25	54M	+0.0%	+0.2%
Q2 25	54M	0.0%	-2.2%
Q3 25	54M	+0.0%	+0.1%
Q4 25	54M	+0.0%	+0.0%

Shares Outstanding

Revenue Per Employee

Period	Revenue/Employee	Employees
Q1 22	$14.1K	82
Q2 22	$16.0K	82
Q3 22	$18.5K	82
Q4 22	$393.1K	127
Q1 23	$17.1K	127
Q2 23	$31.6K	127
Q3 23	$668.2K	127
Q4 23	$1.8K	173
Q1 24	$289	173
Q2 24	$763.1K	173
Q3 24	$5.6K	173
Q4 24	$13.0K	163
Q1 25	$17.3K	163
Q2 25	$27.1K	163
Q3 25	$14.8K	163
Q4 25	$210	100

Revenue / Employee