Prothena Corp plc

Prothena Corp plc insiders are currently net sellers of PRTA stock, showing bearish sentiment over the past 90 days. Total sales of $211.5M outpace purchases of $76.7M, creating a net outflow of $134.8M. However, 46% of these sales are pre-scheduled 10b5-1 plan transactions.

Prothena Corp plc has 26 active insiders who have filed SEC Form 4 transactions in the past 90 days. Capital, Llc Ecor1 (Executive) leads with 13 transactions totaling $114.6M. Co Plc Perrigo (Executive) follows with 1 transactions worth $79.4M. Open-market purchases require insiders to invest their own capital, demonstrating genuine conviction.

The Insider Alignment Score measures the ratio of buying to selling activity on a 0-100 scale. Prothena Corp plc's current score of 27/100 indicates bearish insider sentiment. Scores below 40 indicate selling pressure exceeds buying. Insider selling often reflects diversification needs, tax optimization, or estate planning.

The most recent insider transaction occurred on Apr 10, 2026, when Evans Kingston Anne (Chief Strategy Officer) acquired 100,000 shares at $0.00 per share for $0. This appears to be a discretionary trade.

Based on SEC Form 4 filings from the past 90 days, PRTA insider trading sentiment is currently bearish with an Alignment Score of 27/100. The negative net flow of $134.8M shows more selling than buying. However, 46% of recent transactions are 10b5-1 scheduled trades.

SEC Form 4 is the primary disclosure mechanism for insider trading at publicly traded companies like Prothena Corp plc. Corporate insiders must file within two business days of any transaction, making it one of the most timely sources of executive sentiment. At PRTA, we track all Form 4 filings—currently showing 650 transactions from 26 insiders over 90 days.

A 10b5-1 plan allows Prothena Corp plc executives to pre-schedule stock sales when they don't possess material non-public information. At PRTA, approximately 46% of recent transactions are 10b5-1 trades. This high percentage suggests much of the selling is routine and pre-planned.

You can monitor Prothena Corp plc (PRTA) insider trading activity on this page, which updates within hours of new SEC Form 4 filings. We track all 26 active insiders and provide real-time transaction feeds, the Alignment Score, 10b5-1 vs. discretionary breakdowns, and direct links to SEC EDGAR filings.

Our Alignment Score measures the ratio of insider buying to selling on a scale of 0-100. A score above 70 indicates strong bullish sentiment, while below 30 suggests bearish activity. Prothena Corp plc's current score of 27/100 indicates bearish sentiment with significant insider selling pressure. This is calculated from $76.7M in purchases versus $211.5M in sales over 90 days, resulting in a net flow of -$134.8M.

SEC Form 4 filings are mandatory reports that Prothena Corp plc insiders must submit within 2 business days. Each filing includes the insider's name, relationship, transaction type, shares, and price. Transaction codes: P (purchase), S (sale), A (award), M (option exercise), G (gift). At PRTA, the most common type is "A" with 27 occurrences. The most recent Form 4 was filed on Apr 10, 2026 by Evans Kingston Anne.

Rule 10b5-1 allows corporate insiders to establish pre-scheduled trading plans when they don't possess material non-public information. At Prothena Corp plc, approximately 46% of recent transactions are executed under 10b5-1 plans, while 54% appear to be discretionary trades. This mix provides a balanced picture—some planned, others reflecting real-time decisions.