MAGNITE, INC. (MGNI)
$23.10-$0.26 (-1.11%) Today
Magnite is a supply-side advertising platform that provides technology and yield management solutions to content publishers, enabling them to monetize their digital advertising inventory. Magnite receives a percentage of all advertising inventory that it sells. 43% of Magnite's revenue is derived from connected television, or CTV, streaming platforms, 40% from mobile applications, and the remainder from general websites. Beyond the typical monetization responsibilities inherent to an SSP, Magnite also provides upstream advertising servers to CTV publishers, allowing them to have granular control over direct-sold, programmatic guaranteed, and open-auction logic. Magnite competes with other independent SSPs, supply path optimization solutions, and closed ecosystems like Meta.
| Form 4 transaction type | Transactions | Shares | Total value |
|---|---|---|---|
| Open-market sale | 32 | 1,041,363 | $21.44M |
| Grant or award | 8 | 110,384 | |
| Option exercise | 14 | 1,469,726 | |
| Tax withholding / forfeiture | 7 | 65,011 | |
| Bona-fide gift | 1 | 26,258 |
Dollar totals are shown for open-market purchases and sales only. Grants, option exercises, gifts and tax withholding are reported by share count because they are not trades at a market price.
131 Form 4 filings on record, the earliest from Nov 8, 2024, newest first. Filing history page 1 of 3.
| Date | Insider | Transaction | Security | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sarah Patricia Harden - Director | Open-market sale | Common Stock | 30,550 | $23.31 | $712K | |
| Sarah Patricia Harden - Director | Open-market sale | Common Stock | 18,436 | $24.00 | $442K | |
| David Buonasera - Officer | Tax withholding / forfeiture | Common Stock | 8,102 | $24.73 | $200K | |
| Katie Seitz Evans - Officer | Tax withholding / forfeiture | Common Stock | 11,204 | $24.73 | $277K | |
| Aaron Saltz - Officer | Tax withholding / forfeiture | Common Stock | 5,627 | $24.73 | $139K | |
| Brian Gephart - Officer | Tax withholding / forfeiture | Common Stock | 3,789 | $24.73 | $94K | |
 Michael G. Barrett - Officer | Tax withholding / forfeiture | Common Stock | 10,404 | $24.73 | $257K | |
 David Day - Officer | Tax withholding / forfeiture | Common Stock | 14,170 | $24.73 | $350K | |
| Paul Caine - Director | Open-market sale | Common Stock | 7,500 | $25.00 | $188K | |
| Sean Patrick Buckley - Officer | Tax withholding / forfeiture | Common Stock | 11,715 | $24.73 | $290K | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 8,271 | $24.31 | $201K | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 2,759 | $25.00 | $69K | |
| David Day - Officer | Gift | Common Stock | 26,258 | $0.00 | - | |
| Brian Gephart - Officer | Open-market sale | Common Stock | 12,479 | $24.68 | $308K | |
| Rachel Lam - Director | Open-market sale | Common Stock | 10,000 | $24.16 | $242K | |
| Paul Caine - Director | Open-market sale | Common Stock | 5,000 | $24.35 | $122K | |
| Sean Patrick Buckley - Officer | Option exercise | Common Stock | 28,703 | $13.90 | $399K | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 47,942 | $25.09 | $1.20M | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 19,237 | $23.00 | $442K | |
| Sean Patrick Buckley - Officer | Option exercise | Stock Option (right to buy) | 28,703 | $0.00 | - | |
 Douglas S. Knopper - Director | Open-market sale | Common Stock | 37,337 | $22.72 | $848K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 4,176 | $22.81 | $95K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 2,602 | $24.00 | $62K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 871 | $25.00 | $22K | |
| Katie Seitz Evans - Officer | Option exercise | Common Stock | 20,000 | $5.16 | $103K | |
| Katie Seitz Evans - Officer | Open-market sale | Common Stock | 20,000 | $24.00 | $480K | |
| Katie Seitz Evans - Officer | Option exercise | Employee Stock Option (Right to Buy) | 20,000 | $0.00 | - | |
| Michael G. Barrett - Officer | Option exercise | Common Stock | 293,968 | $5.80 | $1.71M | |
| Michael G. Barrett - Officer | Open-market sale | Common Stock | 293,968 | $22.72 | $6.68M | |
| Michael G. Barrett - Officer | Option exercise | Stock Option (right to buy) | 293,968 | $0.00 | - | |
| Michael G. Barrett - Officer | Option exercise | Common Stock | 38,596 | $5.80 | $224K | |
| Michael G. Barrett - Officer | Open-market sale | Common Stock | 38,596 | $20.35 | $785K | |
| Michael G. Barrett - Officer | Option exercise | Employee Stock Option (Right to Buy) | 38,596 | $0.00 | - | |
| Paul Caine | Open-market sale | Common Stock | 5,000 | $20.64 | $103K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 1,224 | $21.00 | $26K | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 19,233 | $21.03 | $404K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 9,376 | $20.00 | $188K | |
| Michael G. Barrett - Officer | Option exercise | Common Stock | 75,000 | $5.80 | $435K | |
| Michael G. Barrett - Officer | Open-market sale | Common Stock | 75,000 | $19.50 | $1.46M | |
| Michael G. Barrett - Officer | Option exercise | Employee Stock Option (Right to Buy) | 75,000 | $0.00 | - | |
| Sean Patrick Buckley - Officer | Open-market sale | Common Stock | 19,233 | $19.00 | $365K | |
| Douglas S. Knopper | Open-market sale | Common Stock | 37,337 | $18.10 | $676K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 1,057 | $17.00 | $18K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 11,233 | $18.00 | $202K | |
| David Buonasera - Officer | Open-market sale | Common Stock | 1,409 | $19.00 | $27K | |
| Michael G. Barrett - Officer | Option exercise | Common Stock | 100,000 | $5.80 | $580K | |
| Michael G. Barrett - Officer | Open-market sale | Common Stock | 100,000 | $17.50 | $1.75M | |
| Michael G. Barrett - Officer | Option exercise | Employee Stock Option (Right to Buy) | 178,596 | $0.00 | - | |
| Michael G. Barrett - Officer | Option exercise | Employee Stock Option (Right to Buy) | 100,000 | $0.00 | - | |
| Michael G. Barrett - Officer | Option exercise | Common Stock | 178,596 | $5.80 | $1.04M | |
| Michael G. Barrett - Officer | Open-market sale | Common Stock | 178,596 | $16.59 | $2.96M | |
| Paul Caine | Grant or award | Common Stock | 13,798 | $0.00 | - | |
| Diane Yu | Grant or award | Common Stock | 13,798 | $0.00 | - |
A Form 144 is notice of an INTENDED sale, not a completed one. It often precedes the Form 4 that reports the trade actually happening.
| Filed | Filer | Relationship | Shares | Market value | Notice |
|---|---|---|---|---|---|
| SARAH PATRICIA HARDEN | Director | 18,436 | $442K | View on EDGAR | |
| SARAH PATRICIA HARDEN | Director | 30,550 | $712K | View on EDGAR | |
| SEAN BUCKLEY | Officer | 2,759 | $67K | View on EDGAR |
MAGNITE, INC. (MGNI) had 37 insider filings in the last 90 days, with the most recent on 2026-08-28. The full record for MGNI runs to 131 Form 4 filings, the earliest from 2024-11-08. InsiderAlpha tracks every Form 4, Form 144, and 8-K filing in real time.
No insider purchases of MGNI were filed in the last 90 days.
32 insider sales of MGNI were filed in the last 90 days, totaling $21.44M.
This page tracks MGNI Form 4 insider transactions, Form 144 sale notices, and 8-K material event disclosures in one timeline. Annual 10-K and quarterly 10-Q reports live on the company's SEC EDGAR page.
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Every Form 4 below links to the original document on SEC EDGAR, so the numbers on this page can be checked against the filing they came from.
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