GLAUKOS Corp President & COO Joseph E. Gilliam Sells 1,056 Shares for Tax Withholding

This Form 4 filing reports that Joseph E. Gilliam, President and Chief Operating Officer of GLAUKOS Corp, sold 1,056 shares of common stock on June 25, 2026, at a price of $142.57 per share. The transaction was coded as "F" (tax withholding obligation) and "D" (disposition), representing shares withheld by the company to cover tax obligations related to the vesting and delivery of restricted stock units previously granted on March 18, 2021. Following this transaction, Gilliam holds 72,363 shares, which includes 41,983 restricted stock units that have not yet vested or been delivered. The filing was signed by Diana Scherer as Attorney-in-Fact on June 29, 2026. This is a routine transaction related to tax obligations on executive compensation rather than a discretionary sale.