Value
7.2/10data confidence 33%| Component | Sub-score |
|---|---|
| P/S | 4.4 |
| Analyst target | 9.0 |
- ▸Attractively valued
PRTA · Why this verdict
Why Prothena Corporation (PRTA) is rated SELL
Updated
Model-generated analysis — not investment advice. Not a registered investment advisor. Past performance does not guarantee future results.
Show full disclosure ▾Hide full disclosure ▴
About TrendMatrix. TrendMatrix is a publisher of general securities research and market commentary. We publish on a regular schedule. All content is the same for every subscriber in a tier — we do not provide personalized investment advice and we do not take into account any individual subscriber's financial situation, investment objectives, risk tolerance, tax situation, or holdings.
Not investment advice. TrendMatrix is not a registered investment adviser. Our content is for informational and educational purposes only. Consult your own licensed investment adviser, broker, or tax professional before making any investment decision.
Conflicts and positions. The TrendMatrix editorial team frequently holds personal long-term positions in securities discussed. We disclose positions held at the time of publication on each piece. We maintain a trading-window policy: we do not initiate or close positions in the same direction as a TrendMatrix publication within 24 hours before or 72 hours after publication.
No paid promotion. TrendMatrix does not accept payment from any issuer, broker, or third party in exchange for coverage of any security. Our sole compensation is subscription revenue.
No fiduciary duty. No fiduciary, advisory, or agency relationship is created between you and TrendMatrix by reading our content or subscribing to our service.
Performance. Past performance is not indicative of future results. Performance figures reflect the published model only and do not reflect any individual subscriber's actual results.
VerdictSELL
Overall score5.8/10
ConfidenceMEDIUM
MacroNEUTRAL
Thesis pillars
| Pillar | Expectation | Trend |
|---|---|---|
The engine's asymmetry gate passed strongly at 6.1, well above the 1.5 threshold, indicating a favorable modeled risk/reward setup. Engine gate (passed) | The asymmetry ratio should stay well above 1.5 and the favorable setup should continue to hold over the next several months if the thesis plays out. | →Stable |
| CounterA very high modeled asymmetry ratio in a clinical-stage biotech often reflects a binary trial-outcome distribution rather than a genuinely balanced risk/reward trade. | ||
Sentiment data shows analyst price targets imply 121% upside from current levels, reflecting a bullish outside view on the stock. Sentiment breakdown | The gap between price and analyst target should narrow through price appreciation over the next 12 months if the bullish view is well founded. | →Stable |
| CounterA 121% implied upside for a clinical-stage biotech typically prices in success of a specific pipeline catalyst, and the target can be cut sharply if that catalyst disappoints. | ||
The company shows weak fundamental quality, with free cash flow running at roughly -55% of revenue and a Piotroski F-Score of just 3 out of 9. Quality breakdown | The Piotroski F-Score should improve meaningfully off its current 3/9 reading and free cash flow burn should narrow over the next several quarters. | →Stable |
| CounterClinical-stage biotechs routinely score poorly on cash-flow and Piotroski metrics while funding late-stage trials, which does not necessarily indicate an unsound underlying pipeline. | ||
Insiders have been active net buyers, adding roughly 345,000 shares across 5 separate purchases with no offsetting sales, a bullish conviction signal. Insider | Insider buying should continue or at least not reverse into net selling over the next 90 days if insiders see genuine value at current levels. | →Stable |
| CounterInsider purchases ahead of binary clinical catalysts can reflect routine compensation-plan activity rather than a differentiated view on trial outcomes. | ||
Short interest is elevated at roughly 18% of float, and the risk data explicitly frames this level of shorting as justified given the underlying risk profile. Risk breakdown | Short interest should decline toward more typical levels if the risks the shorts are targeting fail to materialize over the next couple of quarters. | →Stable |
| CounterA justified high short interest combined with strong insider buying and a favorable asymmetry ratio could still set up a short squeeze on positive news rather than confirming the bearish case. | ||
The engine's asymmetry gate passed strongly at 6.1, well above the 1.5 threshold, indicating a favorable modeled risk/reward setup.
→StableEngine gate (passed)
- Expectation
- The asymmetry ratio should stay well above 1.5 and the favorable setup should continue to hold over the next several months if the thesis plays out.
CounterA very high modeled asymmetry ratio in a clinical-stage biotech often reflects a binary trial-outcome distribution rather than a genuinely balanced risk/reward trade.
Sentiment data shows analyst price targets imply 121% upside from current levels, reflecting a bullish outside view on the stock.
→StableSentiment breakdown
- Expectation
- The gap between price and analyst target should narrow through price appreciation over the next 12 months if the bullish view is well founded.
CounterA 121% implied upside for a clinical-stage biotech typically prices in success of a specific pipeline catalyst, and the target can be cut sharply if that catalyst disappoints.
The company shows weak fundamental quality, with free cash flow running at roughly -55% of revenue and a Piotroski F-Score of just 3 out of 9.
→StableQuality breakdown
- Expectation
- The Piotroski F-Score should improve meaningfully off its current 3/9 reading and free cash flow burn should narrow over the next several quarters.
CounterClinical-stage biotechs routinely score poorly on cash-flow and Piotroski metrics while funding late-stage trials, which does not necessarily indicate an unsound underlying pipeline.
Insiders have been active net buyers, adding roughly 345,000 shares across 5 separate purchases with no offsetting sales, a bullish conviction signal.
→StableInsider
- Expectation
- Insider buying should continue or at least not reverse into net selling over the next 90 days if insiders see genuine value at current levels.
CounterInsider purchases ahead of binary clinical catalysts can reflect routine compensation-plan activity rather than a differentiated view on trial outcomes.
Short interest is elevated at roughly 18% of float, and the risk data explicitly frames this level of shorting as justified given the underlying risk profile.
→StableRisk breakdown
- Expectation
- Short interest should decline toward more typical levels if the risks the shorts are targeting fail to materialize over the next couple of quarters.
CounterA justified high short interest combined with strong insider buying and a favorable asymmetry ratio could still set up a short squeeze on positive news rather than confirming the bearish case.
TrendMatrix Research · core thesis
Engine thesis — one sentence
PRTA offers a high-asymmetry setup with a large modeled upside and active insider buying, but weak fundamental quality, including heavy cash burn and a low Piotroski score, plus a justified elevated short interest, keep the position speculative.
Falsifiable statement — pillar-level invalidators below. Engine-derived; not personalized advice.
Per-dimension breakdown
Quality
3.6/10data confidence 100%| Component | Sub-score |
|---|---|
| ROE | 0.0 |
| ROA | 0.0 |
| Op margin | 10.0 |
| Current ratio | 5.0 |
| FCF quality | 0.0 |
| Moat | 5.8 |
| Piotroski F | 4.4 |
- ▸Cash-burning: FCF -55% of revenue
Growth
5.0/10data confidence 50%Momentum
6.7/10data confidence 100%| Component | Sub-score |
|---|---|
| RSI | 4.3 |
| MACD | 8.6 |
| OBV | 10.0 |
| MA position | 9.0 |
| Volume | 1.4 |
- ▸Overbought (RSI 73)
- ▸Volume accumulation (rising OBV)
- ▸Above 200-day MA
Sentiment
6.6/10data confidence 100%| Component | Sub-score |
|---|---|
| Analyst rating | 5.0 |
| Price target | 10.0 |
| erm sentiment | 5.0 |
- ▸Analyst upside: 117%
Insider
8.2/10data confidence 75%| Component | Sub-score |
|---|---|
| materiality | 9.0 |
| insider conviction | 8.0 |
| holder change | 7.5 |
- ▸Heavy insider buying — $3,097,110 (0.623% of mkt cap)
Peer rank
6.1/10data confidence 80%| Component | Sub-score |
|---|---|
| value rank | 5.5 |
| quality rank | 2.1 |
| growth rank | 10.0 |
- ▸Industry growth leader
Technical
3.4/10data confidence 100%| Component | Sub-score |
|---|---|
| bollinger | 2.3 |
| support resistance | 1.2 |
| 52w position | 6.7 |
Risk (lower is worse)
3.9/10data confidence 100%| Component | Sub-score |
|---|---|
| short interest | 1.7 |
| days to cover | 0.0 |
| volatility | 0.2 |
| put call | 8.9 |
| implied vol | 3.5 |
| max pain risk | 3.0 |
| debt equity | 9.9 |
- ▸High short interest justified: 18%
- ▸Above max pain $1
Catalyst
6.4/10data confidence 100%| Component | Sub-score |
|---|---|
| erm | 5.0 |
| earnings history | 5.6 |
| earnings timing | 5.0 |
| surprise avg | 10.0 |
How the verdict was assembled
Engine trigger
Quality below minimum threshold.
Engine technical detail
verdict_path:
L1:HARD_BLOCKPassed (8)
- MOMENTUM:6.7>=5.5
- ASYMMETRY:5.9>=1.5
- INSIDER:OK
- 8K:CLEAN
- NEWS_EVENTS:NONE_RECENT
- EARNINGS_PROXIMITY:27d clear
- SEMI_CYCLE_PEAK:CLEAR
- MATERIALS_CYCLE_PEAK:CLEAR
Failed (0)
none
Warning (0)
none
Reward-to-Risk
5.93
Upside
+89.0%
Downside
15.0%
Sizing output
AVOID
Setup— — No clear chart pattern; technical signals are mixed
EdgeInst Constrain — Small cap ($0.5B) below institutional reach
SuitabilitySpeculative — Binary industry: Biotechnology
Investment implication
The L1 gate blocked the positive-verdict path: a hard-floor threshold was breached, so dimensional pillars — including Insider at 8.2 could not lift the engine output above the verdict floor.
The strongest dimensions are Insider at 8.2, Value at 7.2, and Momentum at 6.7; the weakest are Technical at 3.4, Quality at 3.6, and Risk (lower is worse) at 3.9. The V9 engine cleared all gates, producing an asymmetric reward-to-risk of 5.93 and an engine sizing output of AVOID.
What would invalidate the thesis
Falsifying conditions — when triggered, the corresponding pillar's thesis is invalidated.
- P1High Asymmetry Favorable Setup
Trip ifAsymmetry ratio falls below 1.5 from the current 6.1, reversing the favorable risk/reward setup.
- P2Large Analyst Upside Target
Trip ifAnalyst upside falls below 30% from the current 121%, closing most of the price-target gap.
- P3Weak Piotroski Cash Burn Quality
Trip ifPiotroski F-Score rises above 5 out of 9 from the current 3/9, or FCF margin improves above -20% from the current -55%.
- P4Insider Buying Conviction
Trip ifNet insider share count falls below 0 over the next 90 days, reversing the current +345,000 share bullish signal.
- P5Justified High Short Interest Risk
Trip ifShort interest falls below 10% of float from the current 18%, easing the justified short pressure.