MGNI insider buying and SEC filings, explained
Magnite, Inc. · CIK 1595974
Tracked: Forms 3/4/5, 8-K, NT · All filings on sec.gov
Company profile
- Exchanges
- Nasdaq
- Industry (SIC)
- Services-Computer Programming, Data Processing, Etc.
- State of incorporation
- DE
- Fiscal year end
- Dec 31
- Former names
- RUBICON PROJECT, INC.
Insider activity in the last 12 months
Bought
$0
Insiders who bought
0
Sold (not marked 10b5-1)
$861K
Planned sales (10b5-1)
$25.8M
Insider purchases and sales, last 12 months
| Traded | Type | What was filed | Source |
|---|---|---|---|
| Oct 12, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 12,500 shares at about $25.29 ($316K), marked as a 10b5-1 plan trade. Holdings down 9% to 124,901 shares. | SEC filing Filed Oct 14, 2026, 4:30 PM ET |
| Sep 17, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 7,500 shares at $26.50 ($199K), marked as a 10b5-1 plan trade. Holdings down 5% to 137,401 shares. | SEC filing Filed Sep 18, 2026 |
| Sep 17, 2026 | Planned (10b5-1) | Douglas S Knopper (Director) sold 37,337 shares at about $26.28 ($981K), marked as a 10b5-1 plan trade. Holdings down 42% to 51,136 shares. | SEC filing Filed Sep 18, 2026 |
| Sep 14, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 1,165 shares at $24.00 ($28K), marked as a 10b5-1 plan trade. Holdings down <1% to 245,155 shares. | SEC filing Filed Sep 16, 2026 |
| Sep 11, 2026 | Planned (10b5-1) | Katie Seitz Evans (President / COO) sold 13,997 shares at $24.00 ($336K), marked as a 10b5-1 plan trade. Holdings down 3% to 441,800 shares. | SEC filing Filed Sep 11, 2026 |
| Sep 10, 2026 | Planned (10b5-1) | Aaron Saltz (Chief Legal Officer) sold 40,000 shares at about $23.41 ($936K), marked as a 10b5-1 plan trade. Holdings down 15% to 224,389 shares. | SEC filing Filed Sep 11, 2026 |
| Sep 10, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 5,000 shares at about $23.53 ($118K), marked as a 10b5-1 plan trade. Holdings down 3% to 144,901 shares. | SEC filing Filed Sep 11, 2026 |
| Sep 8–9, 2026 | Planned (10b5-1) | Katie Seitz Evans (President / COO) sold 43,385 shares between Sep 8 and Sep 9 at about $23.59 ($1.0M), marked as a 10b5-1 plan trade. Holdings down 9% to 455,797 shares. | SEC filing Filed Sep 10, 2026 |
| Sep 1–2, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 6,414 shares between Sep 1 and Sep 2 at about $23.68 ($152K), marked as a 10b5-1 plan trade. Holdings down 3% to 246,320 shares. | SEC filing Filed Sep 3, 2026 |
| Aug 26–28, 2026 | Planned (10b5-1) | Sarah Patricia Harden (Director) sold 48,986 shares between Aug 26 and Aug 28 at about $23.57 ($1.2M), marked as a 10b5-1 plan trade. Holdings down 30% to 114,751 shares. | SEC filing Filed Aug 28, 2026 |
| Aug 17–18, 2026 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 11,030 shares between Aug 17 and Aug 18 at about $24.48 ($270K), marked as a 10b5-1 plan trade. Holdings down 4% to 293,060 shares. | SEC filing Filed Aug 18, 2026 |
| Aug 14, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 7,500 shares at $25.00 ($188K), marked as a 10b5-1 plan trade. Holdings down 5% to 149,901 shares. | SEC filing Filed Aug 18, 2026 |
| Aug 10, 2026 | Sale | Brian Gephart (Chief Accounting Officer) sold 12,479 shares at about $24.68 ($308K). Holdings down 11% to 106,117 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Aug 12, 2026 |
| Aug 10, 2026 | Sale | Rachel Lam (Director) sold 10,000 shares at about $24.16 ($242K). Holdings down 4% to 230,620 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Aug 12, 2026 |
| Aug 10, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 5,000 shares at about $24.35 ($122K), marked as a 10b5-1 plan trade. Holdings down 3% to 157,401 shares. | SEC filing Filed Aug 12, 2026 |
| Aug 6, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 7,649 shares at about $23.46 ($179K), marked as a 10b5-1 plan trade. Holdings down 3% to 260,836 shares. | SEC filing Filed Aug 7, 2026 |
| Aug 6, 2026 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 67,179 shares at about $24.49 ($1.6M), marked as a 10b5-1 plan trade. Holdings down 18% to 315,805 shares. | SEC filing Filed Aug 7, 2026 |
| Aug 6, 2026 | Planned (10b5-1) | Katie Seitz Evans (President / COO) sold 20,000 shares at $24.00 ($480K), marked as a 10b5-1 plan trade. Holdings down 4% to 496,840 shares. | SEC filing Filed Aug 7, 2026 |
| Aug 6, 2026 | Planned (10b5-1) | Douglas S Knopper (Director) sold 37,337 shares at $22.72 ($848K), marked as a 10b5-1 plan trade. Holdings down 30% to 88,473 shares. | SEC filing Filed Aug 7, 2026 |
| Aug 6, 2026 | Planned (10b5-1) | Michael G. Barrett (CEO and Director) sold 293,968 shares at $22.72 ($6.7M), marked as a 10b5-1 plan trade. Holdings down 42% to 403,074 shares. | SEC filing Filed Aug 7, 2026 |
| Jul 15, 2026 | Planned (10b5-1) | Michael G. Barrett (CEO and Director) sold 38,596 shares at about $20.35 ($785K), marked as a 10b5-1 plan trade. Holdings down 9% to 403,074 shares. | SEC filing Filed Jul 17, 2026 |
| Jul 10, 2026 | Planned (10b5-1) | Paul Caine (Director) sold 5,000 shares at about $20.64 ($103K), marked as a 10b5-1 plan trade. Holdings down 3% to 162,401 shares. | SEC filing Filed Jul 14, 2026 |
| Jul 7, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 1,224 shares at $21.00 ($26K), marked as a 10b5-1 plan trade. Holdings down <1% to 268,485 shares. | SEC filing Filed Jul 9, 2026 |
| Jul 7, 2026 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 19,233 shares at about $21.03 ($404K), marked as a 10b5-1 plan trade. Holdings down 5% to 354,281 shares. | SEC filing Filed Jul 9, 2026 |
| Jul 1, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 9,376 shares at $20.00 ($188K), marked as a 10b5-1 plan trade. Holdings down 3% to 269,709 shares. | SEC filing Filed Jul 2, 2026 |
| Jun 29, 2026 | Planned (10b5-1) | Michael G. Barrett (CEO and Director) sold 75,000 shares at $19.50 ($1.5M), marked as a 10b5-1 plan trade. Holdings down 16% to 403,074 shares. | SEC filing Filed Jul 1, 2026 |
| Jun 17, 2026 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 19,233 shares at $19.00 ($365K), marked as a 10b5-1 plan trade. Holdings down 5% to 373,514 shares. | SEC filing Filed Jun 18, 2026 |
| Jun 16, 2026 | Planned (10b5-1) | Douglas S Knopper (Director) sold 37,337 shares at about $18.10 ($676K), marked as a 10b5-1 plan trade. Holdings down 23% to 125,810 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 15–17, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 13,699 shares between Jun 15 and Jun 17 at about $18.03 ($247K), marked as a 10b5-1 plan trade. Holdings down 5% to 279,085 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 15–16, 2026 | Planned (10b5-1) | Michael G. Barrett (CEO and Director) sold 278,596 shares between Jun 15 and Jun 16 at about $16.92 ($4.7M), marked as a 10b5-1 plan trade. Holdings down 41% to 403,074 shares. | SEC filing Filed Jun 17, 2026 |
| Jun 10, 2026 | Planned (10b5-1) | Douglas S Knopper (Director) sold 10,766 shares at about $15.73 ($169K), marked as a 10b5-1 plan trade. Holdings down 6% to 163,147 shares. | SEC filing Filed Jun 10, 2026 |
| Jun 10, 2026 | Planned (10b5-1) | David T. Pearson (Director) sold 10,766 shares at about $15.65 ($168K), marked as a 10b5-1 plan trade. Holdings down 12% to 79,001 shares. | SEC filing Filed Jun 10, 2026 |
| Jun 1, 2026 | Planned (10b5-1) | David Buonasera (Chief Technology Officer) sold 1,409 shares at $15.00 ($21K), marked as a 10b5-1 plan trade. Holdings down <1% to 292,784 shares. | SEC filing Filed Jun 3, 2026 |
| May 19, 2026 | Sale | Robert F Spillane (Director) sold 10,000 shares at about $13.33 ($133K). Holdings down 19% to 43,917 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 21, 2026 |
| Feb 18, 2026 | Planned (10b5-1) | Adam Lee Soroca (Chief Product Officer) sold 21,529 shares at $12.00 ($258K), marked as a 10b5-1 plan trade. Holdings down 5% to 388,425 shares. | SEC filing Filed Feb 18, 2026 |
| Dec 17, 2025 | Planned (10b5-1) | Adam Lee Soroca (Chief Product Officer) sold 16,656 shares at $17.00 ($283K), marked as a 10b5-1 plan trade. Holdings down 5% to 326,114 shares. | SEC filing Filed Dec 19, 2025 |
| Nov 24, 2025 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 2,213 shares at $14.50 ($32K), marked as a 10b5-1 plan trade. Holdings down 1% to 268,912 shares. | SEC filing Filed Nov 26, 2025 |
| Nov 21, 2025 | Sale | Robert F Spillane (Director) sold 12,500 shares at about $14.22 ($178K). Holdings down 19% to 53,917 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Nov 21, 2025 |
| Nov 18, 2025 | Planned (10b5-1) | Sean Patrick Buckley (President / COO) sold 4,426 shares at about $13.36 ($59K), marked as a 10b5-1 plan trade. Holdings down 2% to 271,125 shares. | SEC filing Filed Nov 18, 2025 |
| Nov 18, 2025 | Planned (10b5-1) | Adam Lee Soroca (Chief Product Officer) sold 10,857 shares at about $13.23 ($144K), marked as a 10b5-1 plan trade. Holdings down 3% to 326,114 shares. | SEC filing Filed Nov 18, 2025 |
66 routine transactions (such as grants, option exercises or tax withholding) are not listed.
Cluster buys
No cluster buys in the last 12 months.
Red flags
No red flags in the last 12 months.
Key events
No key events in the last 12 months.
8-K filings, last 12 months
No 8-K filings in the last 12 months.
Red flags are objective triggers only: the item or form filed, never an opinion.
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