Brian Gephart is CAO at MAGNITE, INC. (MGNI). They have made 6 open-market trades across 1 company since 2023, most recently 2026-10-01.
CIK 0001778484
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 6 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| MGNI | 167,010 | $3.9M |
| LEAF | 123,988 | $1.1M |
| Total | $5.0M |
Shares reported on the most recent Form 4, priced at the 2026-10-02 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| MGNI | SELL | 2026-08-10 | 2026-08-12 | $24.68 | $308K | -4.1% | -3.2% | — |
| MGNI | SELL · 10b5-1 | 2025-09-04 | 2025-09-05 | $24.71 | $1.4M | -4.3% | -22.7% | -42.3% |
| MGNI | SELL | 2025-08-18 | 2025-08-20 | $23.85 | $141K | +16.2% | +17.8% | -39.1% |
| MGNI | SELL | 2025-05-12 | 2025-05-14 | $16.16 | $205K | -1.3% | +4.8% | +36.5% |
| MGNI | SELL | 2025-03-03 | 2025-03-05 | $16.00 | $100K | -6.6% | -35.6% | +17.7% |
| MGNI | SELL · 10b5-1 | 2024-11-18 | 2024-11-19 | $15.60 | $34K | +5.7% | -3.4% | +19.2% |
| MGNI | SELL · 10b5-1 | 2024-11-11 | 2024-11-13 | $15.00 | $32K | -0.9% | -1.7% | +20.7% |
| MGNI | SELL · 10b5-1 | 2024-07-15 | 2024-07-17 | $15.00 | $242K | -1.6% | -14.6% | -16.1% |
| MGNI | SELL | 2023-08-16 | 2023-08-18 | $8.31 | $9K | +4.4% | -2.8% | -4.0% |
| MGNI | SELL | 2023-05-16 | 2023-05-18 | $10.88 | $13K | +1.4% | +14.5% | -28.8% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.