Tandem Diabetes (TNDM) CFO Leigh Vosseller Exercises RSUs, 4,120 Shares

What Happened

• Leigh Vosseller, Chief Financial Officer of Tandem Diabetes Care (TNDM), had restricted stock units (RSUs) convert into 4,120 shares on August 15, 2026 (recorded as exercise/conversion of a derivative). Of those, 1,479 shares were withheld by the issuer to satisfy tax withholding obligations at $22.72 per share (total withholding value $12,201 + $21,402 = $33,603). Net issued shares to Vosseller were 2,641. No shares were sold on the open market.

Key Details

• Transaction date: August 15, 2026; Form 4 filed August 18, 2026.
• Conversion/Acquisition: 4,120 shares recorded as exercise/conversion of derivative (code M) at $0.00 per share.
• Tax withholding (code F): 537 shares ($12,201) and 942 shares ($21,402) withheld at $22.72/share; total withheld value $33,603.
• Net new shares received: 4,120 − 1,479 = 2,641 shares.
• Shares held after the transaction: not specified in the provided filing excerpt.
• Notable footnotes: shares were withheld by the issuer to satisfy tax withholding on vested RSUs (no open-market sale); securities are held in the Leigh A. Vosseller Trust; RSUs were granted under the 2023 Long-Term Incentive Plan and may be settled in stock or cash at the issuer’s discretion.

Context

• This was a vesting/settlement of RSUs (derivative conversion), not an open-market sale — withholding of shares to cover taxes is a routine administrative action and does not necessarily indicate a change in insider sentiment. The filing shows two separate RSU award vintages referenced (May 23, 2024 and May 30, 2025) with staggered vesting schedules per the plan.