COGENT COMMUNICATIONS HOLDINGS, INC.

On June 2, 2025, Cogent Communications Holdings, Inc. (the “Company”) announced that two of its wholly owned subsidiaries, Cogent Communications Group, LLC (f/k/a Cogent Communications Group, Inc.) (“Cogent Group”) and Cogent Finance, Inc. (the “Co-Issuer” and, together with Cogent Group, the “Issuers”), intend to commence an offering of $600.0 million aggregate principal amount of senior secured notes due 2032 (the “Notes”) for issuance in a private placement not registered under the U.S. Securities Act of 1933, as amended (the “Securities Act”). The Notes are being offered and sold only to persons reasonably believed to be qualified institutional buyers in an unregistered offering pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in transactions outside the United States in compliance with Regulation S under the Securities Act. The Notes will be jointly and severally guaranteed on a senior secured basis by each of Cogent Group’s existing and future material domestic subsidiaries (other than the Co-Issuer), subject to certain exceptions. In addition, the Notes will be guaranteed on a senior unsecured basis by the Company; however, the Company will not be subject to the covenants under the indenture governing the Notes (the “Indenture”).

Cogent Group intends to use a portion of the net proceeds from the offering to finance the redemption in full of the Issuers’ outstanding $500.0 million aggregate principal amount of 3.500% senior secured notes due 2026 (the “Existing Secured Notes”). Cogent Group intends to use the remainder of the net proceeds for general corporate purposes and/or to make special or recurring dividends to the Company.

There can be no assurance that the issuance and sale of the Notes will be consummated or that any of the Existing Secured Notes will be redeemed.

On June 2, 2025 the Company issued a press release announcing its intention to commence the offering of the Notes, a copy of which is attached as Exhibit 99.1.

The information in this Current Report on Form 8-K (this “Current Report”) does not constitute an offer to sell or a solicitation of an offer to buy any of the Notes. The offering is not being made to any person in any state or jurisdiction in which the offer, solicitation or sale is unlawful. The Notes have not been and will not be registered under the Securities Act, and may not be offered or sold absent registration or an applicable exemption from registration requirements. This Current Report does not constitute a notice of redemption of the Existing Secured Notes or an offer to tender for, or purchase, any Existing Secured Notes or any other security.