PRTA
Strong SellSinkerProthena Corporation plc · Healthcare · Ireland · $446M cap · $4.3M/day traded
$8.43 -4.6% · close 12 Oct · scored 14 Oct
Sinker: Weak, expensive and falling. Nothing here to keep it afloat.
As of 14 Oct 2026, MoatMap's StockRank for Prothena Corporation plc (PRTA) is 15/100, ranked against 24,000+ stocks in 35 markets (Quality 27, Value 32, Momentum 34, each scored against its sector).
Does StockRank work? Each month we publish how every decile did, whichever way it went. See the record →
ABOUT PROTHENA CORPORATION PLC
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Prothena Corporation plc is a clinical-stage neuroscience company specializing in the discovery and development of novel antibodies and immunotherapies for neurodegenerative diseases. Its robust pipeline targets critical protein misfolding conditions such as amyloidosis, Parkinson's, and Alzheimer's disease. The company leverages deep scientific expertise in protein dysregulation to create targeted treatments addressing significant unmet medical needs.
FINANCIAL SUMMARY (USD)
| Year | 2022 | 2023 | 2024 | 2025 | CAGR | TTM | 2026E | 2027E | Fwd CAGR |
|---|---|---|---|---|---|---|---|---|---|
| Revenue | 53.9M | 91.4M | 135.2M | 9.7M | -43.6% | 54.5M | 83.2M | 24.4M | 58.7% |
| EPS | -2.47 | -2.76 | -2.27 | -4.53 | — | -0.82 | -0.55 | -1.52 | — |
| Shares | 52.1M | 53.7M | 53.8M | 53.8M | +3.3% | 51.3M | — | — | — |
| Debt | 6.5M | 11.8M | 10.8M | 8.4M | 9.0% | 7.0M | — | — | — |
| Equity | 622.0M | 561.4M | 486.9M | 280.5M | -23.3% | — | — | — | — |
| Op CF | -108.8M | -133.9M | -150.1M | -163.6M | — | -60.0M | — | — | — |
| Inv CF | -0.5M | -2.8M | -0.3M | -0.1M | — | — | — | — | — |
| Fin CF | 241.5M | 45.1M | 1.6M | -0.1M | — | — | — | — | — |
No new 52-week low for 16 weeks, 9% above that low, but not back above a rising 50-day average.
Swung more than 61% of stocks we rank over the past year (48% a year).
How this is worked out
StockRank judges the business. The price check reads only the chart: it is the price side of the Momentum score, in words.
The rules: Still falling is a new 52-week low in the last two weeks, at least 25% below the high. Finding a floor is no new low since. Turning up is 20 or more trading days without a new low, at least 10% off it, and back above a rising 50-day average. In an uptrend is above the 200-day average and within 15% of the high.
In 2,112 US drawdowns since 2001, buying while the price was still falling was followed by a further 20% drop 42% of the time. Waiting for a turn like this one cut that to 33%, at about 7% higher prices and with no better returns. Part of that cut is simply not buying: 13% of falls never turned, and waiting kept those out. Among turns that were bought, 38% still fell another 20%, and 33% of turns were followed by a new low within six months. The benefit was largest in crashes such as 2008 and 2020.
What it measures: day-to-day price moves over the past year, as a yearly figure, ranked against every stock we cover. Very calm under 20% a year, Calm 20 to 30%, Average 30 to 40%, Bumpy 40 to 55%, Very bumpy above that.
What we found: across about 13,500 stocks in 34 markets (2002 to 2025), past swings were a good guide to the next year's, and bumpier stocks fell further. How much further changed too much between eras to put a number on it.
Calm is not safe: a calm stock can still slide steadily.
Rules fixed before any data was fetched. Describes the chart, not a recommendation.
SCORE BREAKDOWN
FUNDAMENTALS
SECTOR PEERS
Closest peers in Healthcare, ranked by industry match, size, and score similarity. Cross-listings of PRTA are excluded.
| Ticker | Company | Mkt Cap | StockRank | Signal |
|---|---|---|---|---|
| PRTA | Prothena Corporation plc(you) | $446M | 15 | Strong Sell |
| GHRS | GH Research PLC | $1.8B | 29 | Sell |
| CMHC.SW | Cosmo N.V. | $1.1B | 19 | Strong Sell |
| AMRN | Amarin Corporation plc | $290M | 34 | Sell |
| COPN.SW | Cosmo NV | $1.2B | 25 | Sell |
| ONE.AX | Oneview Healthcare PLC | $93M | 15 | Strong Sell |
| JAZZ | Jazz Pharmaceuticals plc | $15.2B | 91 | Strong Buy |
| UPR.L | Uniphar plc | $1.2B | 67 | Buy |
| PRGO | Perrigo Company plc | $1.9B | 73 | Buy |
| ALKS | Alkermes plc | $7.1B | 58 | Hold |
Peer medians: ROE 2.1% · P/E 21.5x · Gross margin 45.5%
Company Deep Dive
Business segments breakdown, earnings transcript analysis, management credibility scoring, competitive landscape, and scenario modelling.