InsiderTrades

Form 4 for MGNI MAGNITE, INC.

Accepted 2026-08-07 17:14:08 ET · period of report 2026-08-06 · accession 0001865116-26-000007 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
DT 2026-08-07 17:14 2026-08-06 MGNI Buckley Sean Patrick See Remarks M - OptEx $13.90 +28.7K 383.0K +8% +$399.0K
DMT 2026-08-07 17:14 2026-08-06 MGNI Buckley Sean Patrick See Remarks S - Sale+OE $24.49 -67.2K 315.8K -18% -$1.65M
DT 2026-08-07 17:14 2026-08-06 MGNI Buckley Sean Patrick See Remarks M - OptEx $0.00 -28.7K 57.4K -33% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-08-06 M A 28,703 $13.90 382,984 D — — (F1) The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025.
2 Common Common Stock 2026-08-06 S D 47,942 $25.09 335,042 D — — (F1) The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025.
3 Common Common Stock 2026-08-06 S D 19,237 $23.00 315,805 D — — (F1) The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025.
4 Derivative Stock Option (right to buy) 2026-08-06 M D 28,703 $0.00 57,405 D $13.90 · — to 2032-02-01 28,703 Common Stock (F1) The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025. (F3) Granted as compensation for services. (F2) The stock options have fully vested and are immediately exercisable.