Prothena Plc(NASDAQ) PRTA

Current Price$8.53

Market Cap$458.09M

Since IPO (2012)+22%

5 Year-83%

1 Year+39%

1 Month-2%

Prothena Plc last closing stock price
Metric	Price	Date
Last close	USD 8.75	2026-07-21

Prothena Plc stock price return by period
Period	Price return	Price at period start	Period start date
1 week	+1.27%	USD 8.64	2026-07-14
1 month	-2.02%	USD 8.93	2026-06-18
3 month	-18.38%	USD 10.72	2026-04-22
Year to date	-8.38%	USD 9.55	2025-12-31
1 year	+39.11%	USD 6.29	2025-07-21
3 year	-86.54%	USD 65.01	2023-07-21
5 year	-82.96%	USD 51.34	2021-07-22
Since inception	+21.53%	USD 7.20	2012-12-21

Prothena Plc Financials at a Glance

Market Cap

$458.09M

Revenue (TTM)

$57.94M

Net Income (TTM)

-$151.18M

EPS (TTM)

-$2.81

P/E Ratio

-3.11

Dividend

$0.00

Beta (Volatility)

1.39 (Average)

Dividend

$0.00

Beta (Volatility)

1.39 (Average)

Price

$8.53

Volume

284,168.663

Open

$8.69

Price

$8.53

Volume

284,168.663

Open

$8.69

Previous Close

$8.75

Daily Range

$8.48 - $8.79

52-Week Range

$6.51 - $11.80

Estimated Earnings Date

Aug 3, 2026

Dividend

$0.00

Beta (Volatility)

1.39 (Average)

Price

$8.53

Volume

284,168.663

Open

$8.69

Previous Close

$8.75

Daily Range

$8.48 - $8.79

52-Week Range

$6.51 - $11.80

Estimated Earnings Date

Aug 3, 2026

PRTA News

Page 1

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About Prothena Plc

Prothena makes medicines for brain and heart diseases. It helps people with Parkinson's and Alzheimer's. The company targets harmful proteins that damage organs.

Key Medicines in Development

Prasinezumab: Investigational antibody for Parkinson's disease designed to slow motor decline; currently in Phase 3 trials in partnership with Roche.
Coramitug: Therapy for ATTR amyloidosis, a condition where proteins damage the heart; currently in Phase 3 trials managed by Novo Nordisk.
BMS-986446: Anti-tau antibody for Alzheimer's disease that targets protein tangles in the brain; currently in Phase 2 trials with Bristol Myers Squibb.
PRX012: Wholly owned antibody for Alzheimer's disease designed for simple under-the-skin injections; currently in Phase 1 clinical testing.

Strategic Moves and Partnerships

Sold the ATTR amyloidosis business and drug coramitug to Novo Nordisk in July 2021 for up to $1.23 billion.
Entered a global license agreement with Bristol Myers Squibb in July 2023 for the Alzheimer's program BMS-986446.
Partnered with Bristol Myers Squibb in May 2024 for the PRX019 program, receiving an $80 million fee.
Initiated the Phase 3 PARAISO trial for Parkinson's disease with Roche in late 2025.
Reduced the workforce by approximately 63% in June 2025 to lower operating costs and focus on core programs.

What Sets Prothena Apart

The company uses a specialized discovery engine to map proteins that cause disease. Its CYTOPE technology helps reach targets inside cells that were previously undruggable, meaning they could not be treated with existing medicines.

A Look at the Numbers

Net loss reached $21.6 million in Q4 2025, improving 62.7% from Q4 2024.
Operating loss narrowed to $27.2 million in Q4 2025, up 58.1% year-over-year.
Revenue fell to $21,000 in Q4 2025, down 99% from $2.1 million in Q4 2024.
Free cash flow reached negative $27.2 million in Q4 2025, improving 43.2% from Q4 2024.

Bottom Line

Prothena has transitioned into a late-stage biotechnology firm by leveraging high-value partnerships with global pharmaceutical leaders. Recent cost reductions and asset sales have narrowed its focus to the most promising therapies for neurodegenerative and rare diseases.

AI Generated • May 5, 2026

Industry

Biotechnology

Sector

Health Care

Employees

CEO

Gene G. Kinney, PhD

Website

www.prothena.com

Headquarters

Dublin, DU D02 VK60, IE

PRTA Financials

Key Financial Metrics (TTM)

Gross Margin

46.85%

Operating Margin

-217.94%

Net Income Margin

-260.92%

Return on Equity

-49.88%

Return on Capital

-62.70%

Return on Assets

-43.21%

Earnings Yield

-32.15%

Dividend Yield

0.00%

Payout Ratio

0.00%

Stock Overview

Market Cap

$458.09M

Shares Outstanding

52.35M

Volume

284.17K

Avg. Volume

553.88K

Financials (TTM)

Gross Profit

$27.14M

Operating Income

-$126.28M

EBITDA

-$74.72M

Operating Cash Flow

-$81.34M

Capital Expenditure

-$96.00K

Free Cash Flow

-$81.44M

Cash & ST Invst.

$329.46M

Total Debt

$7.65M

Prothena Plc Performance Analysis

Prothena Plc annual revenue and year-over-year revenue growth by fiscal year
Fiscal year	Period end	Revenue	YoY growth
2022	2022-12-31	USD 53,905,000	-73.1%
2023	2023-12-31	USD 91,370,000	69.5%
2024	2024-12-31	USD 135,157,000	47.9%
2025	2025-12-31	USD 9,684,000	-92.8%

Prothena Plc sequential (quarter-over-quarter) revenue growth by fiscal quarter
Fiscal quarter	Period end	QoQ growth
Q2	2025-06-30	56.3%
Q3	2025-09-30	-45.4%
Q4	2025-12-31	-99.1%
Q1	2026-03-31	243157.1%

Prothena Plc annual diluted earnings per share and year-over-year EPS growth by fiscal year
Fiscal year	Period end	Diluted EPS	YoY growth
2022	2022-12-31	USD -2.47	N/A
2023	2023-12-31	USD -2.76	11.9%
2024	2024-12-31	USD -2.27	-17.7%
2025	2025-12-31	USD -4.53	99.4%

Prothena Plc sequential (quarter-over-quarter) diluted earnings per share growth by fiscal quarter
Fiscal quarter	Period end	QoQ growth
Q2	2025-06-30	-108.9%
Q3	2025-09-30	70.9%
Q4	2025-12-31	41.2%
Q1	2026-03-31	250.0%

Revenue Growth Rate

Annual and quarterly growth comparison

Earnings Per Share Growth Rate

Annual and quarterly EPS growth comparison

Quarterly Performance

Name

Q1 2026YOY CHG

Revenue

$51.08M

+1706.4%

Gross Profit

$50.17M

+1673.9%

Gross Margin

98.20%

N/A

Market Cap

$458.09M

N/A

Market Cap/Employee

$6.84M

N/A

Employees

N/A

Net Income

$32.72M

+154.4%

EBITDA

$33.64M

+155.0%

Quarterly Fundamentals

Name

Q1 2026YOY CHG

Total Cash

$329.46M

-21.2%

Total Debt

$7.65M

-25.0%

Accounts Receivable

$0.00

N/A

Inventory

$0.00

N/A

Long Term Debt

$4.76M

-37.1%

Short Term Debt

$2.89M

+10.1%

Return on Assets

-43.21%

N/A

Return on Invested Capital

-39.79%

N/A

Free Cash Flow

$28.88M

+154.1%

Operating Cash Flow

$28.88M

+154.1%

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Questions About PRTA

What is the current price of Prothena Plc?

Prothena Plc is trading at $8.48 per share.

What is the 52-week range for Prothena Plc?

Over the past 52 weeks, Prothena Plc has traded between $6.51 and $11.80.

How much debt does Prothena Plc have?

As of the most recent reporting period, Prothena Plc reported total debt of $7.65M.

How much cash does Prothena Plc have on hand?

Prothena Plc reported $329.46M in cash and cash equivalents in its most recent financial results.

What is Prothena Plc’s dividend yield?

Prothena Plc does not currently have a dividend yield.

Prothena Plc(NASDAQ) PRTA

Prothena Plc Financials at a Glance

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About Prothena Plc

Key Medicines in Development

Strategic Moves and Partnerships

What Sets Prothena Apart

A Look at the Numbers

Bottom Line

PRTA Financials

Key Financial Metrics (TTM)

Stock Overview

Financials (TTM)

Prothena Plc Performance Analysis

Revenue Growth Rate

Earnings Per Share Growth Rate

Quarterly Performance

Quarterly Fundamentals

Other Investments to Explore

People Also Watch

Trending Stocks

Questions About PRTA

What is the current price of Prothena Plc?

What is the 52-week range for Prothena Plc?

How much debt does Prothena Plc have?

How much cash does Prothena Plc have on hand?

What is Prothena Plc’s dividend yield?

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