| Date | Name | Symbol | Type | Security | Shares | Price | Value | Ownership | Reported |
| 10/01/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.4k | $0.00 | $0 | | 10/01/2023 |
| 07/01/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.4k | $0.00 | $0 | | 07/01/2023 |
| 05/30/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 640 | $63.24 | $40.5k | | 05/30/2023 |
| 04/01/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.5k | $0.00 | $0 | | 04/01/2023 |
| 03/13/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 990 | $61.50 | $60.9k | | 03/13/2023 |
| 01/03/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.7k | $0.00 | $0 | | 01/03/2023 |
| 11/29/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1k | $57.50 | $60.4k | | 11/29/2022 |
| 10/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.6k | $0.00 | $0 | | 10/01/2022 |
| 09/12/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 940 | $55.13 | $51.8k | | 09/12/2022 |
| 07/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.5k | $0.00 | $0 | | 07/01/2022 |
| 05/31/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 950 | $60.72 | $57.7k | | 05/31/2022 |
| 04/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.5k | $0.00 | $0 | | 04/01/2022 |
| 03/09/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 725 | $63.27 | $45.9k | | 03/09/2022 |
| 12/08/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 900 | $77.31 | $69.6k | | 12/08/2021 |
| 10/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 10/01/2021 |
| 09/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 850 | $73.78 | $62.7k | | 09/01/2021 |
| 06/03/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 250 | $75.60 | $18.9k | | 06/03/2021 |
| 06/03/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 500 | $75.53 | $37.8k | | 06/03/2021 |
| 03/12/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 850 | $62.69 | $53.3k | | 03/12/2021 |
| 01/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 01/01/2021 |
| 12/09/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 950 | $57.01 | $54.2k | | 12/09/2020 |
| 10/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 10/01/2020 |
| 09/08/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 910 | $66.05 | $60.1k | | 09/08/2020 |
| 07/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 07/01/2020 |
| 06/09/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 1000 | $76.52 | $76.5k | | 06/09/2020 |
| 04/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 04/01/2020 |
| 03/11/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 300 | $82.85 | $24.9k | | 03/11/2020 |
| 01/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 01/01/2020 |
| 12/12/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 570 | $61.53 | $35.1k | | 12/12/2019 |
| 10/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 10/01/2019 |
| 09/10/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 675 | $58.28 | $39.3k | | 09/10/2019 |
| 07/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 07/01/2019 |
| 05/23/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 515 | $57.45 | $29.6k | | 05/23/2019 |
| 04/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 04/01/2019 |
| 01/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 1.8k | $0.00 | $0 | | 01/01/2019 |
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