Prothena (PRTA) CFO Nguyen Tran Sells 57,000 Shares

What Happened
Nguyen Tran, Prothena's Chief Financial Officer and Chief Strategy Officer, had 57,000 restricted stock units (RSUs) vest on July 28, 2026. The RSUs converted to ordinary shares (recorded as an exercise/conversion of a derivative at $0 per share) and 57,000 shares were then surrendered to the issuer to satisfy tax withholding at $8.56 per share, totaling $487,920. This was a withholding/surrender to the company (disposition to issuer), a routine post-vesting tax-related transaction rather than an open-market sale.

Key Details

• Transaction date(s): July 28, 2026; Form 4 filed July 30, 2026 (timely filing).
• Actions recorded: conversion of RSUs to shares (derivative M, $0 exercise) and disposition to issuer (D) of 57,000 shares at $8.56 each.
• Amounts: 57,000 shares surrendered; proceeds/value recorded for the surrendered shares = $487,920.
• Shares owned after transaction: not specified in the filing.
• Footnotes of note:
  • F1: An RSU equals the contingent right to one ordinary share upon vesting.
  • F2: These RSUs were originally granted July 28, 2025 (part of a 95,000 RSU award) and moved from Table I to Table II in this filing.
  • F3: The 57,000 RSUs reported here are fully vested as of July 28, 2026; 38,000 of the original 95,000 RSUs remain subject to vesting.

Context
Because these were RSUs that vested and were converted at $0 exercise price, the subsequent surrender of shares to the issuer appears to be tax withholding/net settlement rather than an intentional cash sale in the market. Such withholding transactions are routine and typically reflect tax obligations on vested awards, not a direct signal of insider sentiment about the company.