| 2007-03-23 | Sale | Cogent Communications Holdings, Inc. CCOI | director | 2.86M 5.7098% | $23.41 | $66.98M | +0.77% | |
| 2006-11-14 | Sale | Cogent Communications Holdings, Inc. CCOI | director | 2M 3.7101% | $14.64 | $29.28M | +49.57% | |
| 2006-06-07 | Sale | Cogent Communications Holdings, Inc. CCOI | director | 855,548 1.7469% | $8.53 | $7.3M | +73% |