$PRTA

SCULLY WILLIAM P purchased $158K of PRTA

SCULLY WILLIAM P purchased 20,000 shares of PROTHENA CORP PUBLIC LTD CO (PRTA) at $7.90 ($0.16M total) on 2026-06-16.

Original reporting
SEC EDGAR · SCULLY WILLIAM P
Published Jun 18, 2026, 3:38 PM UTC
Analysis
alphai AI DeskAI-generated
Added to alphai Jun 18, 2026, 3:39 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.
alphai market briefInsider activity
Primary signal
$PRTA
Bullish
low confidence
Mentioned
$PRTA
Relevance
5/10
alphai data visualization · based on SEC EDGAR
Decision brief

The 30-second read

$PRTABullishLow
01

Why it matters

Traders may treat the insider buy as a small sentiment input, but it does not change the company’s fundamentals or near-term outlook on its own.

02

Market read

New insider-buy disclosure (20,000 shares) provides a modest sentiment datapoint for PRTA.

03

What to watch

No 10b5-1 plan is cited; without context on prior transactions or total ownership changes, the signal strength is uncertain.

Relevance 5/10Novelty 5/10Timing: after-hours/next-session read-through from a newly filed Form 4 (filed 2026-06-18)

Background

The article is a primary-source SEC Form 4 insider transaction disclosure for Prothena (PRTA).

Company-level read

Ticker impact

$PRTABullishLow confidence
Context

Prothena insider William P. Scully (10% owner) filed a Form 4 open-market purchase of 20,000 shares at $7.8995 on 2026-06-16.

Expected impact

Likely limited near-term impact; any effect should be small and fade unless followed by additional disclosures.

Evidence & confidence

The filing is a routine Form 4 transaction with no accompanying guidance, deal, or operational update; insider buys can be informative but are rarely decisive alone.

Market effects

Minimal; this is company-specific insider activity with no sector-wide regulatory/clinical signal.

None indicated.

None indicated.

Counterpoint

The purchase may be discretionary or part of routine liquidity/portfolio management rather than a strong bullish signal.

Key entities

  • PROTHENA CORP PUBLIC LTD CO

    Subject of the Form 4 insider transaction disclosure.

  • SCULLY WILLIAM P

    10% owner who purchased 20,000 shares open-market at $7.8995 on 2026-06-16.

Related articles

$PRTAMed

PRTA's Q2 Loss Narrower Than Expected, Pipeline Progress in Focus

Prothena (PRTA) reported Q2 2026 adjusted loss per share of 32 cents, narrower than the Zacks estimate of a 39-cent loss. Revenues were $1.01 million versus $4.4 million a year earlier, mainly collaboration revenue from Bristol Myers Squibb (BMY) for PRX019. Prothena had $330.3 million cash, no debt, and reaffirmed 2026 net cash use guidance of $18-$23 million.

$PRTAMed

PROTHENA CORP PUBLIC LTD CO (PRTA): Results of Operations and Financial Condition

PROTHENA CORP PUBLIC LTD CO (PRTA) filed an SEC Form 8-K — Results of Operations and Financial Condition. EX-99.1 2 exhibit991q22026earningsre.htm EX-99.1 Document Exhibit 99.1 PRESS RELEASE Prothena Reports Second Quarter 2026 Financial Results an d Business Highlights • Net cash used in operating and investing activities was $25.7 million in the second quarter, and net cash provide