William M. Diefenderfer III is Director at SLM CORP (SLM). They have made 9 open-market trades across 4 companies since 2006, most recently 2026-09-24.
CIK 0001593538
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.
3 open-market purchases totalling $262K since 2006, against 6 sales. Too few scored purchases to measure a record yet.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| NAVI | SELL | 2016-11-17 | 2016-11-21 | $17.65 | $656K | -6.0% | -5.9% | -12.7% |
| NAVI | SELL | 2016-11-17 | 2016-11-21 | $17.65 | $328K | -6.0% | -5.9% | -12.7% |
| CUBE | SELL | 2016-09-09 | 2016-09-09 | $27.25 | $161K | -0.8% | -3.8% | -4.9% |
| NAVI | SELL | 2016-08-19 | 2016-08-23 | $14.20 | $231K | -0.1% | -5.3% | +22.4% |
| SLM | SELL | 2012-11-09 | 2012-11-13 | $16.99 | $292K | -11.9% | +2.2% | +2.2% |
| YSI | BUY | 2008-05-19 | 2008-05-21 | $13.03 | $195K | N/A | N/A | N/A |
| SLM | SELL | 2006-11-21 | 2006-11-22 | $46.54 | $1.2M | -11.9% | +2.2% | +2.2% |
| YSI | BUY | 2006-09-08 | 2006-09-08 | $20.20 | $24K | N/A | N/A | N/A |
| YSI | BUY | 2006-03-13 | 2006-03-13 | $20.96 | $42K | N/A | N/A | N/A |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.