Magnite (MGNI) CTO David Buonasera Sells Shares

What Happened
David Buonasera, Chief Technology Officer of Magnite, sold a total of 6,414 shares in two open-market dispositions: 5,371 shares on 2026-09-01 at $23.42 per share (≈ $125,789) and 1,043 shares on 2026-09-02 at $25.00 per share (≈ $26,075), for combined proceeds of about $151,864. These were sales (not purchases or option exercises), which are often routine monetization events.

Key Details

• Transaction dates and prices: 2026-09-01 — 5,371 shares @ $23.42; 2026-09-02 — 1,043 shares @ $25.00.
• Total shares sold: 6,414; total proceeds: ≈ $151,864.
• Shares owned after transaction: not disclosed in the provided filing excerpt.
• Footnote: Transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by Buonasera on 2025-09-11.
• Filing timeliness: Form filed 2026-09-03 for reporting period 2026-09-01; this appears to be a timely Form 4 filing.

Context
A 10b5-1 trading plan indicates the sales were prearranged, which typically reduces the informational value of the trades about the insider’s current view of the company. Sales are common for insiders for diversification or liquidity and do not necessarily signal negative company-specific news.