What is Prothena Corporation plc (PRTA) stock price today?

Prothena Corporation plc (PRTA) currently trades at $10.87 per share. The stock has a market capitalization of $619.62M and a P/E ratio of —x.

Is PRTA stock a buy, sell, or hold in 2026?

Based on WallStSmart's proprietary analysis, Prothena Corporation plc has a Smart Value Score of 35/100 (Grade D), resulting in a "Sell" investment rating. The Piotroski F-Score is —/9 and Altman Z-Score is —.

What is Prothena Corporation plc's revenue and earnings?

Prothena Corporation plc has trailing twelve-month (TTM) revenue of $9.68M with profit margins of 0.00%. Earnings per share (EPS) is $-4.53.

PRTA

Prothena Corporation plc

NASDAQ: PRTA · HEALTHCARE · BIOTECHNOLOGY

$10.87

-5.56% today

Updated 2026-04-29

Market cap

$619.62M

P/E ratio

—

P/S ratio

63.98x

EPS (TTM)

$-4.53

Dividend yield

—

52W range

$4 – $12

Volume

0.5M

Market cap

$619.62M

P/E ratio

—

P/S ratio

63.98x

EPS (TTM)

$-4.53

Dividend yield

—

52W range

$4 – $12

Volume

0.5M

WallStSmart proprietary scores

out of 100

Grade: D

Sell

Investment rating

2.7

Growth

5.0

Quality

C+

2.5

Profitability

6.0

Valuation

—/9

Piotroski F-Score

—

Altman Z-Score

—

Industry rank

—

View all highly rated stocks (75+) →206 stocks currently score above 75

Price targets

Analyst target

$21.00

+93.19%

12-Month target

—

Intrinsic (DCF)

—

Margin of safety

—

2 Strong Buy2 Buy2 Hold0 Sell1 Strong Sell

Price chart

X-Ray snapshot

Strengths

Insufficient data

Risks

- Thin margins at 0.00%

- Negative free cash flow $-27.16M

- Revenue declining -99.00% QoQ

Key financials

Revenue Net Income Free Cash Flow

Metric	2022	2023	2024	2025	TTM
Revenue	$53.91M	$91.37M	$135.16M	$9.68M	$9.68M
Net income	$-116.95M	$-147.03M	$-122.31M	$-244.09M	$-21.59M
EPS	—	—	—	—	$-4.53
Free cash flow	$-109.28M	$-136.72M	$-150.35M	$-163.72M	$-27.16M
Profit margin	-216.95%	-160.91%	-90.49%	-2,520.57%	—

Recent insider activity

Date	Insider	Type	Shares	Price
2026-04-10	KINGSTON, ANNE EVANS	Buy	100,000	—
2026-03-03	ZAGO, WAGNER M.	Buy	190,000	—
2026-03-03	WALKER, KARIN L	Buy	150,000	—

Peer comparison

Company	Mkt Cap	Score	Growth	Profit	Value	Quality	MoS	Rating
PRTA	$619.62M	35	2.7	2.5	6.0	5.0	—	Hold
LLY	$760.43B	78	10.0	10.0	5.0	6.5	—	Strong Buy
JNJ	$547.28B	59	4.7	9.0	3.3	6.0	-43.54%	Buy
ABBV	$360.63B	63	4.0	8.0	4.7	5.0	-29.31%	Buy
UNH	$336.47B	54	5.3	5.5	7.3	4.8	+42.09%	Buy
AZN	$287.11B	64	6.7	8.0	5.3	5.0	+4.07%	Buy

Smart narrative

Prothena Corporation plc trades at $10.87. Our Smart Value Score of 35/100 indicates the stock is weak. TTM revenue stands at $9.68M.

Frequently asked questions

What is Prothena Corporation plc's stock price?

Prothena Corporation plc (PRTA) trades at $10.87.

Is Prothena Corporation plc overvalued?

Smart Value Score 35/100 (Grade D, Sell).

What is the price target of Prothena Corporation plc (PRTA)?

The analyst target price is $21.00, representing +93.2% upside from the current price of $10.87.

What is Prothena Corporation plc's revenue?

TTM revenue is $9.68M.

Company info

SectorHEALTHCARE

IndustryBIOTECHNOLOGY

CountryUSA

ExchangeNASDAQ

CurrencyUSD

Quick metrics

P/S ratio63.98x

ROE-63.60%

Beta-0.33

50D MA$9.71

200D MA$9.26

Shares out0.05B

Float0.04B

Short ratio—

Avg volume0.5M

Performance

1 week+1.12%

1 month+8.37%

3 months+23.38%

YTD+13.82%

1 year—

3 years—

5 years—

Compare

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