profit from every $100 of sales.
$0$100
Prothena
$8.16-0.85% today
-19.8% in 1 year
1-year low $7.891-year high $11.51
Trading close to its lowest price of the past year.
The essentials
Four questions every investor asks, answered in one line each.
more sales each year, on average, 2022 to 2025.
0%20% a year
It has no yearly profit to compare the price with.
CheapExpensive
It holds more cash than debt.
No debt5 years
Money in, money out
What Prothena sold, what it kept, and what it did with the cash.
Sales went from $53.9 million in 2022 to $9.68 million in 2025, with -$244 million of profit last year.
SalesProfit
Prothena vs. similar companies
How it compares with the largest companies in its industry.
| Company | Profit from $100 of sales | Sales growth a year | Price per $1 of profit |
|---|---|---|---|
| Prothena | No profit yet | ||
 Vertex Pharmaceuticals | 34.5× · Expensive | ||
 Regeneron Pharmaceuticals | 21.9× · Fair price | ||
 Moderna | No profit yet | ||
 CSL | 22.0× · Fair price |
AI analysis
An AI analyst reads Prothena's last five years, its segments, earnings, insiders and peers, and writes the bull case, the bear case and what the price expects.
Run the AI analysisFull statementsIncome, balance sheet and cash flow, year by year
Income statement
| In millions of USD | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| 54 | 91 | 135 | 10 | |
| – | – | – | – | |
| -132 | -191 | -155 | -185 | |
| -131 | -190 | -154 | -184 | |
| -117 | -147 | -122 | -244 | |
| -2.47 | -2.76 | -2.27 | -4.53 | |
| – | – | – | – | |
| -244.1% | -209.1% | -114.4% | -1,905.8% | |
| -217.0% | -160.9% | -90.5% | -2,520.6% |
Balance sheet
| In millions of USD | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| Total assets | 758 | 696 | 547 | 327 |
| Cash | 710 | 619 | 471 | 308 |
| Total debt | 6 | 12 | 11 | 8 |
| Total liabilities | 136 | 135 | 60 | 46 |
| 622 | 561 | 487 | 280 | |
| 47 | 53 | 54 | 54 | |
| -16.5% | -26.3% | -24.5% | -50.5% | |
| -18.8% | -26.2% | -25.1% | -87.0% |
Cash flow
| In millions of USD | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| -109 | -134 | -150 | -164 | |
| 0 | 3 | 0 | 0 | |
| -109 | -137 | -150 | -164 | |
| Dividends paid | – | – | – | – |
| – | – | 0 | 0 | |
| 31 | 41 | 46 | 38 |
Valuation
- –
- 33.1×
- –
- 1.7×
- 43.3×
- –
- –
- -39.1%
- -58.3%
- 0.0%
Profitability
- 46.8%
- -1,905.8%
- -2,520.6%
- -140.9%
- -39.4%
- -27.6%
- -49.9%
- -43.2%
- -39.8%
- 166.8%
Growth
- −43.6%
- –
- −8.9%
- –
- +5.0%
Financial health
- -1.6×
- 0.02
- 2.2%
- –
- 10.43
- 10.43
- 0.17
How it ranks in Healthcare
Each dot is where the company stands among every company over $300M in the sector. Further right is better.
Bottom 11%of 952
Bottom 2%of 886
Bottom 1%of 987
What analysts expect
- Average price target
- $19.00
- Range
- $19.00 – $19.00
- 1 analysts
These targets were collected on May 20, 2026 and our analyst feed has not updated since, so we no longer compare them with today's price.
Recent earnings
Our results feed has not updated since May 21, 2026. Results reported after that are not in this table yet.
| Date | EPS | Expected | Surprise |
|---|---|---|---|
| May 7, 2026 | 0.52 | -0.31 | +267.7% |
| Feb 19, 2026 | -0.44 | -0.45 | +2.2% |
| Nov 6, 2025 | -0.67 | -0.60 | −11.7% |
| Aug 4, 2025 | -1.86 | -1.11 | −67.6% |
| May 8, 2025 | -1.12 | -0.92 | −21.7% |
| Feb 20, 2025 | -1.08 | -1.02 | −5.9% |
| Nov 12, 2024 | -1.10 | -1.18 | +6.8% |
| Aug 8, 2024 | 1.22 | -1.05 | +216.2% |
News
No recent news on file.
Insider trades
Our insider feed has not updated since May 26, 2026. Trades filed after that are not listed yet.
No insider trades on file.
The seven classic investing rulebooks
0/7Passes 0 of 7. Each bar is how well the company fits that investor's published rules, from 0 to 100; 60 or more counts as a pass.
Warren Buffett
27No pass
Benjamin Graham
57No pass
Philip Fisher
39No pass
Peter Lynch
40No pass
Joel Greenblatt
0No pass
Charlie Munger
41No pass
Terry Smith
33No pass
Questions about Prothena
Is Prothena a good stock to buy?
A business with weak numbers that is not profitable yet. 0 of the 7 famous investors' published rulebooks we apply pass it. Whether it suits you depends on your goals and the price you pay; invest-like never tells anyone to buy or sell. The AI analysis lays out the case for and against. Read the Prothena AI analysis
What does Prothena do?
Prothena Corporation plc, a late-stage clinical company, focuses on discovery and development of novel therapies for life-threatening diseases in the United States. It is in Biotechnology.
Does Prothena pay a dividend?
No. Prothena does not pay a dividend at the moment; in 2025 it returned $139,000 to shareholders by buying back its own shares.
Is Prothena stock halal?
No. Prothena does not pass our halal screen: its cash and confirmed interest-bearing investments are 73% of its market value, at or above the 33% limit. How we check
How has Prothena stock done over the past year?
Down 19.8% over the past twelve months, to $8.16. It traded between $7.89 and $11.51 and is 29.1% below its high.
Who are Prothena's competitors?
The largest listed companies in the same industry are Vertex Pharmaceuticals, Regeneron Pharmaceuticals, Moderna and CSL. The peers table on this page compares their profit, growth and price with Prothena's.
Prices: daily closes to Nov 13, 2026. Fundamentals: company reports via invest-like data.