MAZELSKY JONATHAN JAY 4

What Happened
Jonathan J. Mazelsky, President & CEO and a director of IDEXX Laboratories (IDXX), exercised stock options and sold shares in late February 2026. On Feb 26 he exercised 23,326 option-derived shares at $141.60 per share (cash paid ~$3.30M) and on Feb 27 he exercised 197 shares at $505.53 (cash paid ~$99.6K) — total exercised = 23,523 shares. On Feb 26 he sold 23,326 shares in a series of open-market trades at prices roughly $650.00–$663.04 per share, producing aggregate proceeds of about $15.34M. The exercised shares match the number sold, indicating the exercised shares were immediately sold.

Key Details

• Transaction dates: Feb 26, 2026 (primary exercise + all open-market sales) and Feb 27, 2026 (exercise of 197 shares).
• Exercise (code M): 23,326 @ $141.60 (cost ~$3,302,962) and 197 @ $505.53 (cost ~$99,589).
• Open-market sales (code S): 23,326 shares across multiple trades on Feb 26 for total proceeds ≈ $15,338,082 (prices ranged ~ $650.00–$663.04; detailed weighted averages shown in footnotes F1–F13).
• Footnotes F14/F15: options were from grants that vested over time (one grant vested in installments beginning Feb 14, 2018; another vested on Feb 14, 2026).
• The Form 4 was filed Mar 2, 2026 (within required reporting window — filing appears timely).
• Shares owned after the transactions are not specified in the provided excerpt of the filing.
• Transaction codes: M = option exercise/conversion; S = open-market sale. The $0.00 “Disposed” entries reflect disposition of derivative securities upon exercise.

Context
This is a routine insider option exercise with simultaneous sales (commonly used to cover exercise costs, tax withholding, or to monetize vested awards). The filing is factual: it shows option vesting and near-immediate sale of the exercised shares rather than an independent open‑market purchase by the insider.