Company · CIK 0001595974 · SIC 7370 — Services-Computer Programming, Data Processing, Etc. · Nasdaq

MAGNITE, INC. · MGNI

Insider activity reported against this company. All insider holders · On EDGAR ↗

Period1M 3M 6M 1Y 2Y All datashares as filed — not split-adjusted

Open-market buys & salesbuys $0 · 0sales $4.0M · 9net −$4.0M

Reported at this company — common stock

Trade	Reported (ET)	Insider	Shares	Avg price	Total	Owned after	Δ stake	Flags
Sep 17, 2026 SForm 4 →	Sep 18, 4:06 pm EDT	Paul CaineDirector	7,500	$26.50	$198,750	137,401	−5.18%	10b5-1
Sep 17, 2026 SForm 4 →	Sep 18, 4:05 pm EDT	Douglas S KnopperDirector	37,337	$26.28	$981,216	51,136	−42.2%	10b5-1
Sep 14, 2026 SForm 4 →	Sep 16, 4:23 pm EDT	David BuonaseraCHIEF TECHNOLOGY OFFICER	1,165	$24.00	$27,960	245,155	−0.47%	10b5-1
Sep 14, 2026 SForm 4 →	Sep 16, 4:20 pm EDT	Robert F SpillaneDirector	10,363	$23.76	$246,225	57,715	−15.2%
Sep 14, 2026 MForm 4 →	Sep 16, 4:20 pm EDT	Robert F SpillaneDirector	10,363	$5.17	$53,577	68,078	—
Sep 11, 2026 SForm 4 →	Sep 11, 4:19 pm EDT	Katie Seitz EvansSee Remarks	13,997	$24.00	$335,928	441,800	−3.07%	10b5-1
Sep 10, 2026 SForm 4 →	Sep 11, 4:15 pm EDT	Aaron SaltzCHIEF LEGAL OFFICER	40,000	$23.41	$936,400	224,389	−15.1%	10b5-1
Sep 10, 2026 SForm 4 →	Sep 11, 4:11 pm EDT	Paul CaineDirector	5,000	$23.53	$117,650	144,901	−3.34%	10b5-1
Sep 8, 2026 SForm 4 →	Sep 10, 4:39 pm EDT	Katie Seitz EvansSee Remarks	43,385	$23.59	$1,023,301	455,797	−8.69%	10b5-1
Sep 8, 2026 MForm 4 →	Sep 10, 4:39 pm EDT	Katie Seitz EvansSee Remarks	13,546	$5.16	$69,897	499,182	—	10b5-1
Sep 1, 2026 SForm 4 →	Sep 3, 4:56 pm EDT	David BuonaseraCHIEF TECHNOLOGY OFFICER	6,414	$23.68	$151,864	246,320	−2.54%	10b5-1

Trade	Reported (ET)	Insider	Shares	Avg price	Total	Owned after	Δ stake	Flags
Sep 14, 2026 MForm 4 →	Sep 16, 4:20 pm EDT	Robert F SpillaneDirector	10,363	—	—	0	—
Sep 8, 2026 MForm 4 →	Sep 10, 4:39 pm EDT	Katie Seitz EvansSee Remarks	13,546	—	—	0	—	10b5-1