Prothena Corporation plc Ordinary Shares (PRTA) Stock Price

PRTAStock

$8.35−17.24%52W

Market Cap$428.66M

P/E—

PEG Ratio—

Div yield—

Beta-0.23

PRTA Share Price Chart

Favorite Metrics

Price vs S&P 500 (26W)-31.21%

Price vs S&P 500 (4W)-0.56%

VGM Score62.76

Book Value / Share (Quarterly)$5.54

P/TBV (Annual)1.02x

Indicated Dividend (Annual)$0.00

Revenue Growth (3Y)-43.57%

Cash Flow / Share (Quarterly)$-1.17

Price vs S&P 500 (YTD)-24.49%

Net Profit Margin (TTM)-80.67%

EPS (TTM)$-0.83

10-Day Avg Trading Volume0.62M

EPS Excl Extra (TTM)$-0.83

Revenue Growth (5Y)60.83%

EPS (Annual)$-4.53

ROI (Annual)-87.03%

Net Profit Margin (5Y Avg)-591.09%

Cash / Share (Quarterly)$5.57

Revenue Growth QoQ (YoY)-77.15%

ROA (Last FY)-74.69%

Revenue Growth TTM (YoY)427.32%

EBITD / Share (TTM)$-1.02

ROE (5Y Avg)-28.55%

Operating Margin (TTM)-101.80%

Cash Flow / Share (Annual)$-3.04

P/B Ratio1.49x

P/B Ratio (Quarterly)1.79x

Net Income / Employee (Annual)$-3,643,200

EV / Revenue (TTM)2.58x

Net Interest Coverage (TTM)-1575.00x

ROA (TTM)-13.21%

EV / EBITDA (TTM)2.09x

EPS Incl Extra (Annual)$-4.53

Current Ratio (Annual)7.72x

Quick Ratio (Quarterly)24.82x

3-Month Avg Trading Volume0.52M

52-Week Price Return-17.24%

Revenue / Employee (TTM)$813,900

Tangible BV / Share (Quarterly)$6.66

P/S Ratio (Annual)44.27x

Asset Turnover (Annual)0.03x

52-Week High$11.80

Operating Margin (5Y Avg)-549.63%

EPS Excl Extra (Annual)$-4.53

CapEx CAGR (5Y)-7.15%

Tangible BV CAGR (5Y)8.84%

26-Week Price Return-21.30%

Quick Ratio (Annual)7.57x

13-Week Price Return-3.58%

Total Debt / Equity (Annual)0.00x

Current Ratio (Quarterly)25.05x

Enterprise Value$140.47M

Revenue / Share Growth (5Y)51.42%

Asset Turnover (TTM)0.16x

Book Value / Share Growth (5Y)2.47%

Revenue / Employee (Annual)$144,500

Pretax Margin (Annual)-2073.82%

Cash / Share (Annual)$5.71

3-Month Return Std Dev42.70%

Net Income / Employee (TTM)$-656,600

ROE (Last FY)-87.03%

EPS Basic Excl Extra (Annual)$-4.53

P/FCF (TTM)14.84x

Receivables Turnover (TTM)52.40x

Total Debt / Equity (Quarterly)0.00x

EPS Incl Extra (TTM)$-0.83

Receivables Turnover (Annual)52.40x

ROI (TTM)-14.98%

P/S Ratio (TTM)7.86x

Pretax Margin (5Y Avg)-508.41%

Revenue / Share (Annual)$0.18

Tangible BV / Share (Annual)$7.15

Forward P/E70.42x

Price vs S&P 500 (52W)-32.78%

Year-to-Date Return-12.57%

5-Day Price Return-0.95%

EPS Normalized (Annual)$-4.53

ROA (5Y Avg)-24.52%

Net Profit Margin (Annual)-2520.57%

Month-to-Date Return-0.36%

Cash Flow / Share (TTM)$-1.36

EBITD / Share (Annual)$-3.97

Operating Margin (Annual)-2216.44%

ROI (5Y Avg)-28.55%

EPS Basic Excl Extra (TTM)$-0.83

P/TBV (Quarterly)1.01x

P/B Ratio (Annual)1.83x

Pretax Margin (TTM)-81.33%

Book Value / Share (Annual)$5.21

Price vs S&P 500 (13W)-6.27%

Beta-0.23x

P/FCF (Annual)4.66x

Revenue / Share (TTM)$1.05

ROE (TTM)-14.98%

52-Week Low$7.73

vGradeB

gGradeB

mGradeB

vgmGradeB

PRTA Earnings Surprise History

Quarter	Report date	EPS estimate	EPS actual	Surprise
Q2 2026	Aug 6, 2026	-$0.38	-$0.31	+18.39%(+$0.07)
Q1 2026	May 7, 2026	-$0.30	$0.68	+324.00%(+$0.99)
Q4 2025	Feb 19, 2026	-$0.46	-$0.46	+0.67%(+$0.00)
Q3 2025	Nov 6, 2025	-$0.54	-$0.67	-24.65%(-$0.13)
Q2 2025	Aug 4, 2025	-$1.79	-$1.73	+3.31%(+$0.06)

PRTA Analyst Recommendations

Jun 2026

Jul 2026

Aug 2026

Sep 2026

3.75

Industry Peers — Pharmaceuticals(574)

Symbol	Value Score	Growth Score	Momentum Score	P/S Ratio (TTM)	Revenue Growth TTM (YoY)	Gross Margin (TTM)	EPS Growth (5Y)	Price
PRTAProthena Corporation plc Ordinary Shares	B	B	B	7.9x	427.3%	—	—	$8.35
LLYEli Lilly & Co.	D	B	A	14.9x	49.6%	83.4%	27.6%	$1257.03
JNJJohnson & Johnson	D	C	B	6.2x	7.8%	67.7%	14.9%	$255.56
ABBVABBVIE INC.	D	C	A	7.8x	10.4%	72.8%	-2.9%	$285.42
MRKMerck & Co., Inc.	D	C	A	5.4x	4.6%	77.3%	21.2%	$145.95
NVSNovartis AG	C	C	B	4.9x	3.3%	75.0%	15.3%	$150.62
AZNAstraZeneca PLC	C	B	B	4.3x	8.6%	81.3%	21.9%	$165.41
ABTAbbott Laboratories	C	C	B	3.9x	8.1%	56.8%	8.2%	$104.89
NVONovo-Nordisk A/S	B	C	C	3.5x	5.6%	80.7%	20.7%	$38.83
PFEPfizer Inc.	C	D	A	2.6x	-0.2%	74.7%	-3.5%	$29.58
VRTXVertex Pharmaceuticals Inc	D	C	B	10.1x	10.2%	86.0%	8.3%	$499.74
BMYBristol-Myers Squibb Co.	B	B	B	2.5x	3.1%	71.7%	—	$59.75
GSKGSK plc American Depositary Shares (Each representing two Ordinary Shares)	C	C	B	2.3x	5.0%	73.6%	-0.5%	$49.51
SNYSanofi American Depositary Shares (Each representing one-half of one ordinary share)	B	D	B	1.8x	13.4%	72.8%	-8.2%	$40.61
REGNRegeneron Pharmaceuticals Inc	C	C	A	5.2x	9.3%	86.0%	6.3%	$790.74
TAKTakeda Pharmaceutical Company Limited American Depositary Shares (each representing 1/2 of a share of Common Stock)	C	C	A	2.1x	3.1%	65.5%	-12.6%	$19.67
TEVATeva Pharmaceutical Industries Limited	D	C	A	2.8x	4.1%	52.9%	—	$41.50
ONCBeOne Medicines Ltd. American Depositary Shares	D	B	B	6.3x	31.1%	88.5%	—	$369.06
RPRXRoyalty Pharma plc Class A Ordinary Shares	D	D	A	13.8x	10.0%	—	-12.1%	$60.96
ZTSZOETIS INC.	C	C	B	3.5x	1.4%	71.6%	12.0%	$79.38
ALNYAlnylam Pharmaceuticals, Inc.	D	A	C	6.5x	95.1%	79.7%	—	$231.83
ROIVRoivant Sciences Ltd. Common Shares	D	F	B	3215.5x	-67.6%	81.2%	—	$33.53
UTHRUnited Therapeutics Corp	C	C	B	7.2x	2.5%	86.1%	19.3%	$533.12
GMABGenmab A/S ADS	D	C	A	5.5x	22.3%	93.0%	6.8%	$37.00
VTRSViatris Inc. Common Stock	B	C	A	1.5x	4.4%	40.3%	—	$18.66
INSMInsmed, Inc.	F	A	C	18.5x	185.8%	83.5%	—	$96.27
ASNDAscendis Pharma A/S Ordinary Share	D	A	B	11.9x	113.3%	91.3%	—	$225.25
JAZZJazz Pharmaceuticals, Inc.	B	C	B	3.0x	12.6%	88.4%	-1.4%	$210.23
BBIOBridgeBio Pharma, Inc. Common Stock	F	A	B	18.2x	202.4%	94.4%	—	$66.39
CORTCorcept Therapeutics Inc.	F	C	A	14.3x	16.0%	98.3%	-0.5%	$110.16
ELANElanco Animal Health Incorporated Common Stock	D	B	B	2.3x	11.9%	55.4%	29.9%	$23.55
SMMTSummit Therapeutics Inc. Common Stock	F	—	C	12187.5x	—	—	—	$14.63
RDYDr. Reddy's Laboratories Limited American Depositary Shares	D	C	B	3.1x	-0.9%	61.4%	16.5%	$13.07
BMRNBioMarin Pharmaceuticals Inc	C	C	B	3.1x	11.2%	79.6%	-17.0%	$54.68
MDGLMadrigal Pharmaceuticals, Inc. Common Stock	D	A	C	8.1x	149.0%	91.5%	—	$449.74
CRNXCrinetics Pharmaceuticals, Inc.	F	A	A	213.8x	2928.4%	—	—	$84.95
CYTKCytokinetics Inc.	F	D	B	127.3x	-21.1%	—	—	$61.95
PTGXProtagonist Therapeutics, Inc	F	B	B	29.5x	34.8%	—	—	$128.75
TGTXTG Therapeutics, Inc.	D	B	B	10.3x	76.1%	82.4%	—	$53.97
AXSMAxsome Therapeutics, Inc	D	B	C	10.6x	56.9%	93.2%	—	$157.14
ARWRArrowhead Research Corporation	D	A	C	11.8x	16.9%	—	—	$55.90
ABVXAbivax SA American Depositary Shares	—	—	C	—	—	—	—	$88.13
SYRESpyre Therapeutics, Inc. Common Stock	—	—	B	5995.2x	—	—	—	$79.90
IONSIonis Pharmaceuticals, Inc. Common Stock	D	D	C	8.2x	-7.5%	98.2%	—	$42.94
ALKSAlkermes Inc. plc	D	C	B	4.1x	10.8%	84.6%	—	$41.22
PRAXPraxis Precision Medicines, Inc. Common Stock	F	—	B	789.2x	—	—	—	$241.76
AMRXAmneal Pharmaceuticals, Inc. Class A Common Stock	D	C	A	2.0x	9.3%	39.3%	-18.4%	$19.18
KNSAKiniksa Pharmaceuticals International, plc Class A Ordinary Shares	D	B	A	7.3x	58.9%	89.8%	—	$78.59
RYTMRhythm Pharmaceuticals, Inc. Common Stock	F	B	C	24.7x	53.5%	70.9%	—	$86.17
LGNDLigand Pharmaceuticals Inc.	D	B	B	20.3x	54.9%	95.4%	—	$295.54
BLTEBelite Bio, Inc American Depositary Shares	—	—	B	—	—	—	—	$142.78

About Prothena Corporation plc Ordinary Shares

Prothena is a late-stage clinical biotechnology company developing treatments for neurodegenerative and amyloid diseases using its proprietary CYTOPE platform, which targets intracellular disease pathways in the brain and body. The company's pipeline includes Prasinezumab for Parkinson's disease, Coramitug for ATTR amyloidosis, and partnered programs targeting Alzheimer's disease and ALS. Prothena combines wholly-owned and partnered assets to address protein-dysregulation disorders with significant unmet medical needs.

PRTA Next Earnings Report

Report dateNov 5, 2026

QuarterQ3 2026

Report timeAMC

EPS estimate-$0.30

Revenue estimate$8.21M

Also reporting on Nov 5, 2026

Scheduled date with consensus estimates — both can change before the company reports.

Earnings calendar for November 2026

PRTA Insider Transactions

BuyOct 2, 2026
SCULLY WILLIAM P
Beneficial Owner of more than 10% of a Class of Security
Shares: 100,000Value: $857,240
BuySep 29, 2026
SCULLY WILLIAM P
Beneficial Owner of more than 10% of a Class of Security
Shares: 162,000Value: $1.41M
BuySep 28, 2026
SCULLY WILLIAM P
Beneficial Owner of more than 10% of a Class of Security
Shares: 103,500Value: $889,872
BuySep 18, 2026
SCULLY WILLIAM P
Beneficial Owner of more than 10% of a Class of Security
Shares: 100,000Value: $843,460
BuySep 2, 2026
SCULLY WILLIAM P
Beneficial Owner of more than 10% of a Class of Security
Shares: 27,000Value: $255,739

Open-market buys and sells filed with the SEC over the last 90 days. Grants, gifts and option exercises are excluded.

All insider transactions for October 2026

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Same SIC sector, outside this company's own industry.

Analyst Sentiment

3.8

Buy

Consensus rating

52-Week Range

Low$7.73

High$11.80