| Date | Name | Symbol | Type | Security | Shares | Price | Value | Ownership | Reported |
| 06/06/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $62.23 | $149.4k | | 06/06/2023 |
| 03/07/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $63.51 | $152.4k | | 03/07/2023 |
| 01/03/2023 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 01/03/2023 |
| 12/06/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 4.8k | $57.36 | $275.3k | | 12/06/2022 |
| 12/01/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2022 |
| 09/07/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $53.85 | $129.2k | | 09/07/2022 |
| 06/07/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $59.20 | $142.1k | | 06/07/2022 |
| 03/08/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $62.72 | $150.5k | | 03/08/2022 |
| 01/03/2022 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 01/03/2022 |
| 12/13/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $77.26 | $185.4k | | 12/13/2021 |
| 12/07/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $77.90 | $187k | | 12/07/2021 |
| 12/01/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2021 |
| 09/07/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $74.13 | $177.9k | | 09/07/2021 |
| 06/07/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $76.09 | $182.6k | | 06/07/2021 |
| 03/05/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $57.64 | $138.3k | | 03/05/2021 |
| 02/24/2021 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/24/2021 |
| 12/07/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $57.93 | $139k | | 12/07/2020 |
| 12/03/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $58.01 | $139.2k | | 12/03/2020 |
| 12/01/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 2.4k | $0.00 | $0 | | 12/01/2020 |
| 09/08/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $65.54 | $157.3k | | 09/08/2020 |
| 06/05/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $76.65 | $184k | | 06/05/2020 |
| 03/06/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $84.72 | $203.3k | | 03/06/2020 |
| 02/14/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/14/2020 |
| 01/08/2020 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $68.61 | $164.7k | | 01/08/2020 |
| 12/06/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $62.44 | $149.9k | | 12/06/2019 |
| 09/05/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $59.90 | $143.8k | | 09/05/2019 |
| 06/06/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $58.64 | $140.7k | | 06/06/2019 |
| 05/01/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 05/01/2019 |
| 03/06/2019 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 2.4k | $48.92 | $117.4k | | 03/06/2019 |
| 12/06/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3k | $46.68 | $140k | | 12/06/2018 |
| 09/06/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3k | $54.98 | $164.9k | | 09/06/2018 |
| 06/06/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3k | $52.63 | $157.9k | | 06/06/2018 |
| 03/06/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3k | $43.36 | $130.1k | | 03/06/2018 |
| 02/21/2018 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Grant | common stock | 9.6k | $0.00 | $0 | | 02/21/2018 |
| 12/06/2017 | COGENT COMMUNICATIONS HOLDINGS, INC. | CCOI | Sale | common stock | 3k | $44.54 | $133.6k | | 12/06/2017 |
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