B+
Bull case
25%
Probability
Target price
$18.00
Analysis reference price unavailable
Analysis 2026-08-08 · RankAlpha Sentiment Codex
PRTA
ProthenaANasdaq / Pharmaceuticals, Biotechnology & Life Sciences
Last Price
Quote time unavailable
Current thesis
Prothena retains a large cash position and multiple partnered late-stage programs. PADOVA findings, ongoing Phase 3 trials, and potential milestone payments support long-term optionality [#SEC-8K-2026-08-06].
Posture
Constructive
Lead driver
Sentiment
What changed
Sentiment remains the lead driver in the composite, 7D delta +5.9.
What can break
Cash guidance is lower than the prior midpoint after share repurchases, and continued development spending could pressure runway.
Momentum
39
Value
41
Sentiment
87
Setup hits (3d)
0 · Net Neutral
AI TargetsBase $9.50 · Bull $18.00 · Bear $5.50Analysis 2026-08-08; returns require an exact persisted reference.
Data freshness
Prices
Unavailable: Price unavailable
Fundamentals
As of 2026-08-17 • Vendor: Data Vendor v1
Scores
As of 2026-09-11 • Model: HYBRID_IC_RP
AI Memo
As of 2026-08-08 • Model: RankAlpha Sentiment Codex
Investment thesisAs of 2026-09-11
Investment thesis
As of 2026-09-11
Grade is the composite factor band; factor scores use a 0–100 scale. Confidence describes evidence quality, not a probability of return. Score date: 2026-09-11. Definitions
Supporting evidence
What
Grade A · Constructive
Confidence Medium · Net Neutral
Target $21.40
Why
Momentum39 · Δ7d +3.9
Value41 · Δ7d -0.0
Sentiment87 · Δ7d +5.9
So what
Strength-led posture (Net Neutral). Favor watchlist adds and disciplined entries.
Confirming evidence
- • Sentiment remains the lead driver in the composite, 7D delta +5.9.
Contradictions & invalidation
- • Cash guidance is lower than the prior midpoint after share repurchases, and continued development spending could pressure runway.
- • Clinical-trial failure, delay, or regulatory setbacks across partnered programs.
- • The thesis remains dependent on partner execution and clinical outcomes years away.
Catalyst clock
2026-08-06
Q2 results reset cash outlook
Lead driver: Sentiment · See AI snapshot
Momentum
39
9% active weight
Current posture
7d trendImproving
Δ7d
+3.9
Δ21d
+8.0
Value
41
28% active weight
Current posture
7d trendFlat
Δ7d
-0.0
Δ21d
+0.1
Sentiment
87
62% active weight
Current posture
7d trendImproving
Δ7d
+5.9
Δ21d
-0.8
Why this grade
Composite grade A. Momentum 39.4 / Value 41.2 / Sentiment 87.0
Scenario snapshot
Scenario probability is memo-authored likelihood, not forecast certainty. Targets belong to the analysis dated 2026-08-08. Scenario method
Most likely
B
Base case
50%
Probability
Target price
$9.50
Analysis reference price unavailable
Analysis 2026-08-08 · RankAlpha Sentiment Codex
B-
Bear case
25%
Probability
Target price
$5.50
Analysis reference price unavailable
Analysis 2026-08-08 · RankAlpha Sentiment Codex
Fundamentals (TTM)As of 2026-08-17
Fundamentals (TTM)
As of 2026-08-17
Market Cap
$455.87M
Beta
-0.11
Shares Out
51.34M
P/E (TTM) · Derived
-2.0
P/S (TTM)
41.56
P/FCF (TTM) · Derived
-7.58
Rev YoY
-77.1%
EPS YoY
-84.7%
Gross Margin
+93.2%
Op Margin
-109.8%
Net Debt
-$299.16M
Current Ratio
25.05
As of 2026-09-11 • Updated nightlySource: Internal modelMethods & Data