Horn Keith 4

What Happened
Keith Horn, a director of Amarin Corporation plc (AMRN), had a derivative conversion/RSU vesting on April 18, 2026 that resulted in the acquisition of 838 shares. To satisfy tax withholding, 403 of those shares were withheld by the issuer at $14.98 per share, totaling $6,037. The exercise/conversion reported a $0 exercise price; after withholding Horn retained a net 435 shares (838 acquired less 403 withheld).

Key Details

• Transaction date: April 18, 2026; Form 4 filed April 21, 2026 (timely).
• Acquired: 838 shares via exercise/conversion of a derivative (code M) reported at $0.00.
• Withheld (tax payment): 403 shares (code F) at $14.98 each = $6,037 (this withholding is by the issuer, not an open-market sale).
• Shares owned after transaction: not disclosed in the provided excerpt.
• Notable footnotes: amounts reflect a prior ADS ratio change; the reported conversion relates to RSUs granted April 18, 2024 that vest in installments (each RSU represents a contingent right to 20 Ordinary Shares or cash). Footnote clarifies withholding was for tax liability and not a market sale.

Context
This appears to be a routine vesting/conversion of equity awards (RSUs) with issuer withholding to cover taxes — common corporate practice and not an open-market sale. For retail investors, such withholding is neutral procedural activity rather than a direct insider sale signal.