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SEC EDGAR$PRTA

SCULLY WILLIAM P purchased $439K of PRTA

SCULLY WILLIAM P purchased 50,000 shares of PROTHENA CORP PUBLIC LTD CO (PRTA) at $8.79 ($0.44M total) on 2026-08-20.

Original reporting
SEC EDGAR · SCULLY WILLIAM P
Published Aug 21, 2026, 6:32 PM UTC
Analysis
AlphAI AI DeskAI-generated
Added to AlphAI Aug 21, 2026, 6:34 PM UTC. Informational, not investment advice.
How this was made
AlphAI summarizes source reporting and applies a structured AI analysis for relevance, timing, sentiment and ticker impact. Always verify material claims with the original publisher.
About AlphAI AI DeskScoring methodologyReport an issue
AlphAI market briefInsider activity
Primary signal
$PRTA
Neutral
low confidence
Mentioned
$PRTA
Relevance
5/10
AlphAI data visualization · based on SEC EDGAR
Decision brief

The 30-second read

$PRTANeutralLow
01

Why it matters

The filing provides a fresh, primary source of insider activity but limited material impact.

02

Market read

Minor insider purchase; unlikely to move the stock significantly.

03

What to watch

Potential upcoming clinical data releases for Prothena may amplify relevance of insider activity.

Relevance 5/10Novelty 4/10Timing: post‑market 2026‑08‑20

Background

SEC Form 4 filing discloses insider transaction for Prothena Corp (PRTA).

Company-level read

Ticker impact

$PRTANeutralLow confidence
Context

Form 4 shows insider William Scully bought 50,000 shares at $8.79, increasing his stake to 800,000.

Expected impact

Minimal short‑term movement; no actionable trade signal.

Evidence & confidence

Purchase size (~$0.44 M) is modest for a 10% owner; market likely already priced the stake.

Market effects

Sector

None

Regional

None

Global

None

Counterpoint

What could challenge this read

Insider buying could be a subtle bullish cue if future guidance improves.

Key entities

  • company
    Prothena Corp Public Ltd Co

    Biopharma company listed on NASDAQ (PRTA).

  • insider
    William Scully

    10% owner executing a direct purchase.

Read at source← All news

Full insider trading history

This story covers one filing. See everything behind it: every insider buy and sell on record, 10b5-1 plans, late filings, and which officers and directors are trading.

PRTA insider trading history →

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