| Date | Name | Symbol | Type | Security | Shares | Price | Value | Ownership | Reported |
| 06/01/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $61.07 | $117.3k | | 06/01/2023 |
| 03/01/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $64.49 | $123.8k | | 03/01/2023 |
| 01/03/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 01/03/2023 |
| 12/05/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $57.45 | $110.3k | | 12/05/2022 |
| 12/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $58.15 | $111.6k | | 12/01/2022 |
| 12/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2022 |
| 09/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $53.51 | $102.7k | | 09/01/2022 |
| 06/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $60.03 | $115.2k | | 06/01/2022 |
| 03/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $62.94 | $120.8k | | 03/01/2022 |
| 01/03/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 01/03/2022 |
| 12/14/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $76.77 | $147.4k | | 12/14/2021 |
| 12/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $74.92 | $143.9k | | 12/01/2021 |
| 12/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2021 |
| 06/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $74.96 | $143.9k | | 06/01/2021 |
| 05/19/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 5k | $74.66 | $373.3k | | 05/19/2021 |
| 03/10/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $60.43 | $116k | | 03/10/2021 |
| 02/24/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/24/2021 |
| 02/24/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/24/2021 |
| 12/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2020 |
| 12/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3.8k | $57.94 | $222.5k | | 12/01/2020 |
| 09/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $67.47 | $129.5k | | 09/01/2020 |
| 06/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $78.28 | $150.3k | | 06/01/2020 |
| 03/02/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $77.44 | $148.7k | | 03/02/2020 |
| 02/14/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/14/2020 |
| 12/31/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $66.08 | $126.9k | | 12/31/2019 |
| 12/02/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $61.76 | $118.6k | | 12/02/2019 |
| 10/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 250 | $54.80 | $13.7k | | 10/01/2019 |
| 09/03/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $59.77 | $114.8k | | 09/03/2019 |
| 07/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 250 | $59.28 | $14.8k | | 07/01/2019 |
| 06/03/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $57.41 | $110.2k | | 06/03/2019 |
| 05/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 05/01/2019 |
| 04/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 250 | $53.73 | $13.4k | | 04/01/2019 |
| 03/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1.9k | $48.99 | $94.1k | | 03/01/2019 |
| 01/02/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 250 | $44.51 | $11.1k | | 01/02/2019 |
| 05/11/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2k | $50.36 | $100.7k | | 05/11/2018 |
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