MAGNITE (MGNI) President Sean Buckley Exercises Options, Sells Shares

What Happened

• Sean Patrick Buckley, President, Revenue & Market Strategy at MAGNITE, exercised 28,703 stock options on 2026-08-06 at $13.90 per share (cost $398,972) and had the related derivative cancelled. On the same day he sold a total of 67,179 shares in two open-market transactions — 47,942 shares at $25.09 ($1,202,865) and 19,237 shares at $23.00 ($442,451) — generating combined gross proceeds of $1,645,316. The transactions were reported on a Form 4 filed 2026-08-07.

Key Details

• Transaction date: 2026-08-06 (Form 4 filed 2026-08-07; timely)
• Option exercise: 28,703 shares acquired at $13.90 each (total $398,972)
• Sales: 47,942 shares @ $25.09 and 19,237 shares @ $23.00 (total proceeds ~$1,645,316)
• Derivative disposition: 28,703 option units reported disposed at $0.00 (reflects the option being exercised/cancelled)
• Footnotes: Trades were effected under a Rule 10b5-1 trading plan adopted Sept 10, 2025 (F1); options were fully vested and exercisable (F2); options granted as compensation (F3)
• Shares owned after the transactions: Not specified in the provided filing excerpt

Context

• This filing shows an option exercise coupled with significant open-market sales. The dual reporting of an M-line for acquisition and a derivative disposal at $0.00 is standard when options are exercised and the related option interest is extinguished.
• The sales were made under a pre-established Rule 10b5-1 plan (per footnote), which typically means the sales were scheduled according to a plan rather than ad hoc insider timing. Purchases (option exercise) can signal insider confidence, but routine or planned sales are common for tax/liquidity needs and do not by themselves indicate a change in company outlook.