Thurman Alex R. 4

What Happened
Alex R. Thurman, CFO of Glaukos Corp (GKOS), disposed of a total of 4,771 shares on March 23–24, 2026. The transactions consisted of two issuer tax-withholding transactions (total 3,250 shares) and one open-market sale of 1,521 shares executed under a pre-established Rule 10b5-1 plan. The combined proceeds (or value of shares withheld) total approximately $504,048. These were dispositions (sales/withholdings), which are typically routine tax or plan-driven actions rather than outright purchases.

Key Details

• Dates and amounts:
  • 2026-03-23: 1,230 shares withheld for taxes at $106.84 — $131,413 (F)
  • 2026-03-24: 1,521 shares sold open market at $105.24 — $160,070 (S)
  • 2026-03-24: 2,020 shares withheld for taxes at $105.23 — $212,565 (F)
• Total shares disposed: 4,771; total value ≈ $504,048.
• Transaction codes: S = open-market sale; F = shares withheld by issuer to satisfy tax withholding on RSU vesting.
• Sales executed under a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025 (per footnote).
• Footnotes note unvested restricted stock units: one footnote references 9,761 RSUs not yet vested and another references 5,230 RSUs not yet vested.
• Filing: Form 4 filed March 25, 2026; based on the transaction dates this appears to be timely (no late filing flag shown).
• Shares owned after the transactions are not specified in the provided excerpt of the filing.

Context
The F-coded transactions represent the issuer withholding shares to cover tax withholding obligations when RSUs vest (a net settlement), not an independent open-market sale. The S-coded sale was part of a pre-established 10b5-1 plan, which indicates the sale was preplanned rather than a discretionary, contemporaneous trade. For retail investors, remember that tax-withholding disposals and 10b5-1 sales are often routine and do not necessarily signal the insider’s view on the company’s near-term prospects.