Exhibit 99.1

FOR IMMEDIATE RELEASE

Cogent Communications Reports Third Quarter 2026 Results

Financial and Business Highlights

[WASHINGTON, D.C. November 5, 2026] Cogent Communications Holdings, Inc. (NASDAQ: CCOI) (“Cogent”, or the “Company”) today announced service revenue of $231.2 million for the three months ended September 30, 2026, a decrease of 1.8% from the three months ended June 30, 2026 and a decrease of 4.4% from the three months ended September 30, 2025.

Foreign exchange rates negatively impacted service revenue growth from the three months ended June 30, 2026 to the three months ended September 30, 2026 by $0.3 million, and negatively impacted service revenue growth from the three months ended September 30, 2025 to the three months ended September 30, 2026 by $0.5 million. On a constant currency basis, service revenue decreased by 1.7% from the three months ended June 30, 2026 to the three months ended September 30, 2026, and decreased by 4.2% from the three months ended September 30, 2025 to the three months ended September 30, 2026.

On-net service is provided to customers located in buildings that are physically connected to Cogent’s network by Cogent facilities. On-net revenue was $137.9 million for the three months ended September 30, 2026, an increase of 1.9% from the three months ended June 30, 2026 and an increase of 1.9% from the three months ended September 30, 2025.

Off-net customers are located in buildings directly connected to Cogent’s network using other carriers’ facilities and services to provide the last mile portion of the link from the customers’ premises to Cogent’s network. Off-net revenue was $76.6 million for the three months ended September 30, 2026, a decrease of 9.3% from the three months ended June 30, 2026 and a decrease of 19.5% from the three months ended September 30, 2025.

Wavelength revenue was $16.0 million for the three months ended September 30, 2026, an increase of 7.8% from the three months ended June 30, 2026 and an increase of 57.0% from the three months ended September 30, 2025.

Non-core services are legacy services, which Cogent acquired and continues to support but does not actively sell. Non-core revenue was $0.7 million for the three months ended September 30, 2026, $0.9 million for the three months ended June 30, 2026 and $1.4 million for the three months ended September 30, 2025.

GAAP gross profit is defined as total service revenue less network operations expense, depreciation and amortization and equity-based compensation included in network operations expense. GAAP gross margin is defined as GAAP gross profit divided by total service revenue. GAAP gross profit decreased by 1.6% from the three months ended June 30, 2026 to $56.7 million for the three months ended September 30, 2026 and increased by 13.7% from the three months ended September 30, 2025.

GAAP gross margin was 24.5% for the three months ended September 30, 2026, 24.5% for the three months ended June 30, 2026 and 20.6% for the three months ended September 30, 2025.

Non-GAAP gross profit represents service revenue less network operations expense, excluding equity-based compensation and amounts shown separately (depreciation and amortization expense). Non-GAAP gross margin is defined as Non-GAAP gross profit divided by total service revenue. Non-GAAP gross profit decreased by 0.4% from the three months ended June 30, 2026 to $110.2 million for the three months ended September 30, 2026 and decreased by 0.6% from the three months ended September 30, 2025.

Non-GAAP gross margin was 47.6% for the three months ended September 30, 2026, 47.0% for the three months ended June 30, 2026 and 45.8% for the three months ended September 30, 2025.

Net cash provided by operating activities was $3.8 million for the three months ended September 30, 2026, $3.2 million for the three months ended June 30, 2026 and $3.1 million for the three months ended September 30, 2025.

IP Transit Services Agreement

On May 1, 2023, the closing date of the Sprint acquisition, Cogent and T-Mobile USA, Inc. (“TMUSA”), a Delaware corporation and direct subsidiary of T-Mobile US, Inc., a Delaware corporation (“T-Mobile”), entered into an agreement for IP transit services (the “IP Transit Services Agreement”), pursuant to which TMUSA will pay Cogent an aggregate of $700.0 million, consisting of (i) $350.0 million paid in equal monthly installments during the first year after the closing date of the Sprint acquisition and (ii) $350.0 million paid in equal monthly installments over the subsequent 42 months. Amounts paid under the IP Transit Services Agreement were $16.7 million for the three months ended September 30, 2026, $33.3 million for the three months ended June 30, 2026 and $25.0 million for the three months ended September 30, 2025. The $8.3 million monthly payment for July 2026 was paid to Cogent on June 30, 2026. Amounts paid under the IP Transit Services Agreement were $75.0 million for the nine months ended September 30, 2026 and $75.0 million for the nine months ended September 30, 2025.

Earnings before interest, taxes, depreciation and amortization (EBITDA), was $48.9 million for the three months ended September 30, 2026, $46.1 million for the three months ended June 30, 2026 and $48.8 million for the three months ended September 30, 2025.

EBITDA margin was 21.1% for the three months ended September 30, 2026, 19.6% for the three months ended June 30, 2026 and 20.2% for the three months ended September 30, 2025.

EBITDA, as adjusted, for cash payments made to the Company under the IP Transit Services Agreement, was $73.9 million for the three months ended September 30, 2026, $71.1 million for the three months ended June 30, 2026 and $73.8 million for the three months ended September 30, 2025. The $8.3 million monthly payment for July 2026 paid to Cogent on June 30, 2026 was not included in EBITDA, as adjusted, for cash payments made to the Company under the IP Transit Services Agreement, for the three months ended June 30, 2026 and was included in the period it related to the three months ended September 30, 2026.

EBITDA margin, as adjusted for cash paid under the IP Transit Services Agreement, was 32.0% for the three months ended September 30, 2026, 30.2% for the three months ended June 30, 2026 and 30.5% for the three months ended September 30, 2025.

Basic and diluted net (loss) earnings per share were $(0.62) and $(0.62) for the three months ended September 31, 2026, $1.39 and $1.38 for the three months ended June 30, 2026, and $(0.87) and $(0.87) for the three months ended September 30, 2025, respectively. The gain on a sale of ten owned data centers was $130.7 million and included in earnings per share for the three months ended June 30, 2026.

Total customer connections decreased by 3.0% from September 30, 2025 to 114,678 as of September 30, 2026 and decreased by 1.0% from June 30, 2026. On-net customer connections decreased by 0.5% from September 30, 2025 to 87,326 as of September 30, 2026 and decreased by 0.8% from June 30, 2026. Off-net customer connections decreased by 12.0% from September 30, 2025 to 22,453 as of September 30, 2026 and decreased by 2.5% from June 30, 2026. Wavelength customer connections increased by 55.5% from September 30, 2025 to 2,722 as of September 30, 2026 and increased by 11.3% from June 30, 2026. Non-core customer connections were 2,177 as of September 30, 2026, 2,348 as of June 30, 2026 and 3,244 as of September 30, 2025.

The number of on-net buildings increased by 128 on-net buildings from September 30, 2025 to 3,665 as of September 30, 2026 and increased by 38 on-net buildings from June 30, 2026.

Purchases of 2032 Secured Notes

During the three months ended September 30, 2026, Cogent purchased $118.4 million par value of its 2032 secured notes for $106.7 million at an average price of $90.071 resulting in a gain of $11.3 million. Total purchases of Cogent’s 2032 secured notes through September 30, 2026 were for $138.8 million of par value for $125.4 million at an average price of $90.348 resulting in a total gain of $12.9 million.

Purchase of 2027 Unsecured Notes

During the three months ended September 30, 2026, Cogent purchased $50.0 million par value of its 2027 unsecured notes for $49.6 million at an average price of $99.25, resulting in a gain of $0.1 million.

Optical Wave Network

Acquiring the Sprint network has allowed Cogent to construct a wavelength network using predominantly owned fiber. This enabled Cogent to expand its product offerings to include optical wavelength services. As of September 30, 2026, Cogent was offering optical wavelength services in 1,151 locations in the United States, Mexico and Canada.

Quarterly Dividend Program

On November 4, 2026, Cogent’s Board voted to suspend its dividend program.

The payment of any future dividends and any other returns of capital will be at the discretion of the Board and may be reduced, eliminated or increased and will be dependent upon Cogent’s financial position, results of operations, available cash, cash flow, capital requirements, limitations under Cogent’s debt indentures and other factors deemed relevant by the Board.

Conference Call and Website Information

Cogent will host a conference call with financial analysts at 8:30 a.m. (ET) on November 5, 2026 to discuss Cogent’s operating results for the third quarter of 2026. 

Investors and other interested parties may access the call as follows:

A live audio webcast of the earnings call is also available in the “Events” section of Cogent’s website at www.cogentco.com/events. A replay of the webcast, together with the press release, will be available on the website following the earnings call.  A downloadable file of Cogent’s “Summary of Financial and Operational Results” and a transcript of its conference call will also be available on Cogent’s website following the conference call. 

About Cogent Communications

Cogent Communications (NASDAQ: CCOI) is a multinational, Tier 1 facilities-based ISP. Cogent specializes in providing businesses with high-speed Internet access, Ethernet transport, optical wavelength, optical transport and colocation services. Cogent’s facilities-based, all-optical IP network backbone provides services in 309 markets globally.

Cogent Communications is headquartered at 2450 N Street, NW, Washington, D.C. 20037. For more information, visit www.cogentco.com. Cogent Communications can be reached in the United States at (202) 295-4200 or via email at info@cogentco.com.

# # #

COGENT COMMUNICATIONS HOLDINGS, INC., AND SUBSIDIARIES

Summary of Financial and Operational Results

(1) In connection with the acquisition of the U.S. long-haul fiber network (including the non-U.S. extensions thereof) of Sprint Communications (now Cogent Fiber LLC) and its subsidiaries (the “Wireline Business”), Cogent began to provide optical wavelength services and optical transport services over its fiber network.

(2) Consists of legacy services of companies whose assets or businesses were acquired by Cogent.

(3) See Schedules of Non-GAAP measures below for definitions and reconciliations to GAAP measures.

(4) Network operations expense excludes equity-based compensation expense of $490, $506, $570, $319, $319, $97 and $330 in the three-month periods ended March 31, 2025 through September 30, 2026 respectively. Network operations expense includes excise taxes, including Universal Service Fund fees, of $20,200, $19,998, $19,188, $19,786, $19,490, $18,889 and $18,860 in the three-month periods ended March 31, 2025 through September 30, 2026, respectively.

(5) In connection with the acquisition of the Wireline Business, Cogent classified revenue and customer connections as follows:

(6) GAAP gross profit is defined as total service revenue less network operations expense, depreciation and amortization and equity-based compensation included in network operations expense. GAAP gross margin is defined as GAAP gross profit divided by total service revenue.

(7) Non-GAAP gross profit represents service revenue less network operations expense, excluding equity-based compensation and amounts shown separately (depreciation and amortization expense). Non-GAAP gross margin is defined as non-GAAP gross profit divided by total service revenue. Management believes that non-GAAP gross profit and non-GAAP gross margin are relevant measures to provide investors. Management uses them to measure the margin available to the company after network service costs, in essence a measure of the efficiency of the Company’s network.

(8) Excludes equity-based compensation expense of $7,523, $4,158, $8,362, $4,489, $7,244, $7,545 and $7,545 in the three-month periods ended March 31, 2025 through September 30, 2026, respectively.

(9) Through February 5, 2026, Cogent was party to an interest rate swap agreement (the “Swap Agreement”) that has the economic effect of modifying the fixed interest rate obligation associated with its now discharged Senior Secured 2026 Notes to a variable interest rate obligation based on the Secured Overnight Financing Rate (“SOFR”) so that the interest payable on Cogent’s 2026 Notes effectively became variable based on overnight SOFR. Interest expense includes payments of $9,880 and $4,078 for the three-month periods ended December 31, 2025 and March 31, 2026, respectively, related to the Swap Agreement. Under GAAP, changes in the valuation of the Swap Agreement are classified with interest expense in the condensed consolidated statements of comprehensive income (loss).

(10) Includes cash payments under the IP Transit Services Agreement, as discussed above, of $25.0 million for each of the periods from March 31, 2025 to June 30, 2026. The $8.3 million monthly payment for July 2026 was received on June 30, 2026 and excluded from EBITDA, as adjusted for the three months ended June 30, 2026 and included in the three months ended September 30, 2026 since it relates to the three months ended September 30, 2026.

(11) In connection with the acquisition of the Wireline Business, Cogent acquired 482 technical buildings. Cogent converted 52 of those buildings to Cogent Data Centers and 87 into Cogent Edge Data Centers.

(12) In connection with the acquisition of the Wireline Business, Cogent hired 942 total employees, including 75 quota bearing sales employees and 114 sales employees.

(13) Net-centric revenue under the commercial agreement (the “CSA”) with TMUSA for colocation and connectivity services(predominantly on-net revenue) was

Net-centric customer connections under the CSA were:

(14) Amounts Due from T-Mobile include 1) Due from T-Mobile, IP Transit Services Agreement, current portion, 1) Due from T-Mobile, IP Transit Services Agreement, long-term portion and 3) Due from T-Mobile, Purchase Agreement, all amounts net of their applicable discounts. These amounts totaled $265,090, $244,821, $224,167, $203,120, $181,670, $151,479 and $137,538 as of March 31, 2025 to September 30, 2026, respectively.

(15) The $8.3 million cash payment under the IP Transit Services Agreement for July 2026 was received on June 30, 2026 and excluded from EBITDA, as adjusted for the three months ended June 30, 2026 and included for the three months ended September 30, 2026 since it relates to the three months ended September 30, 2026.

Schedules of Non-GAAP Measures

EBITDA, EBITDA, as adjusted for cash payments made to the Company under the IP Transit Services Agreement, EBITDA margin and EBITDA, as adjusted for cash payments made to the Company under the IP Transit Services Agreement, margin

EBITDA represents net cash flows provided by operating activities plus changes in operating assets and liabilities, cash interest expense and cash income tax expense. Management believes the most directly comparable measure to EBITDA calculated in accordance with generally accepted accounting principles in the United States, or GAAP, is net cash provided by operating activities. The Company also believes that EBITDA is a measure frequently used by securities analysts, investors, and other interested parties in their evaluation of issuers. EBITDA, as adjusted for cash payments under the IP Transit Services Agreement with T-Mobile, represents EBITDA and cash payments made to the Company under the IP Transit Agreement. EBITDA margin is defined as EBITDA divided by total service revenue. EBITDA, as adjusted for cash payments made to the Company under the IP Transit Agreement margin is defined as EBITDA, as adjusted for cash payments made to the Company under the IP Transit Agreement, divided by total service revenue.

The Company believes that EBITDA, EBITDA, as adjusted for cash payments made to the Company under the IP Transit Services Agreement, EBITDA margin and EBITDA as adjusted for cash payments made to the Company under the IP Transit Services Agreement margin are useful measures of its ability to service debt, fund capital expenditures, pay dividends and expand its business. The company believes its EBITDA, as adjusted for cash payments made to the Company under the IP Transit Services Agreement, is a useful measure because it includes recurring cash flows stemming from the IP Transit Services Agreement that are of the same type as contracted payments under commercial contracts. The measurements are an integral part of the internal reporting and planning system used by management as a supplement to GAAP financial information. EBITDA, EBITDA, as adjusted for cash payments made to the Company under the IP Transit Agreement, EBITDA margin and EBITDA as adjusted for cash payments made to the Company under the IP Transit Agreement margin are not recognized terms under GAAP and accordingly, should not be viewed in isolation or as a substitute for the analysis of results as reported under GAAP, but rather as a supplemental measure to GAAP. For example, these measures are not intended to reflect the Company’s free cash flow, as they do not consider certain current or future cash requirements, such as capital expenditures, contractual commitments, and changes in working capital needs, interest expenses and debt service requirements. The Company’s calculations of these measures may also differ from the calculations performed by its competitors and other companies and as such, their utility as a comparative measure is limited.

EBITDA, and EBITDA, as adjusted, for cash payments made to the Company under the IP Transit Services Agreement, are reconciled to net cash provided by operating activities in the table below.

Constant currency revenue is reconciled to service revenue as reported in the tables below.

Constant currency impact on revenue changes – sequential periods