Updated Jul 16, 2026 · Last SEC filing 2026-07-14
MAGNITE, INC. (MGNI) has filed 26 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-07-14. 3 Form 8-K material event filings were reported by MGNI in the last 90 days. 29 Form 144 notices of proposed sale were filed for MGNI stock. InsiderAlpha tracks every MGNI SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SEC CIK | 0001595974 |
|---|
| Form 4 filings (90d) | 26 |
|---|---|
| Form 8-K filings (90d) | 3 |
| Form 144 notices (90d) | 29 |
| Latest Form 4 filing | 2026-07-14 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Caine Paul | Insider | S — Open-market sale [10b5-1] | 5.0K | $20.64 | $103K | SEC | |
| Buonasera David | CHIEF TECHNOLOGY OFFICER | S — Open-market sale | 1.2K | $21.00 | $26K | SEC | |
| Buckley Sean Patrick | See Remarks | S — Open-market sale | 19.2K | $21.03 | $404K | SEC | |
| Buonasera David | CHIEF TECHNOLOGY OFFICER | S — Open-market sale | 9.4K | $20.00 | $188K | SEC | |
| BARRETT MICHAEL G. | CEO | M — Option exercise | 75.0K | $5.80 | $435K | SEC | |
| BARRETT MICHAEL G. | CEO | S — Open-market sale | 75.0K | $19.50 | $1.46M | SEC | |
| Buckley Sean Patrick | See Remarks | S — Open-market sale | 19.2K | $19.00 | $365K | SEC | |
| Buonasera David | CHIEF TECHNOLOGY OFFICER | S — Open-market sale | 1.4K | $19.00 | $27K | SEC | |
| Knopper Douglas S | Insider | S — Open-market sale | 37.3K | $18.10 | $676K | SEC | |
| Buonasera David | CHIEF TECHNOLOGY OFFICER | S — Open-market sale | 11.2K | $18.00 | $202K | SEC | |
| BARRETT MICHAEL G. | CEO | M — Option exercise | 100.0K | $5.80 | $580K | SEC | |
| BARRETT MICHAEL G. | CEO | S — Open-market sale | 100.0K | $17.50 | $1.75M | SEC | |
| BARRETT MICHAEL G. | CEO | M — Option exercise | 178.6K | $5.80 | $1.04M | SEC | |
| BARRETT MICHAEL G. | CEO | S — Open-market sale | 178.6K | $16.59 | $2.96M | SEC | |
| Buonasera David | CHIEF TECHNOLOGY OFFICER | S — Open-market sale | 1.1K | $17.00 | $18K | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for MAGNITE, INC. (MGNI). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| BARRETT MICHAEL G. | 10 | $8.36M |
| Buonasera David | 7 | $588K |
| Knopper Douglas S | 3 | $845K |
| Buckley Sean Patrick | 3 | $924K |
| Caine Paul | 2 | $103K |
Form 144 must be filed before insiders sell restricted or control stock above SEC thresholds. A cluster of Form 144 notices often precedes a wave of insider distribution.
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in MGNI insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
Open the live MGNI dashboard on InsiderAlpha for real-time alerts, charting, and full historical filing search.