Cogent Communications Holdings faces securities class-action allegations that it overstated the growth prospects and revenue potential of its optical-wavelength backlog. The proposed class covers investors who purchased or otherwise acquired Cogent securities from February 29, 2024, through May 1, 2026, and the lead-plaintiff deadline is September 21, 2026. Kaplan Fox & Kilsheimer LLP and Hagens Berman Sobol Shapiro LLP have issued separate investor notices concerning the case and related investigations. The allegations point to a 20% sequential backlog decline and the removal of 1,500 orders in February 2025, subsequent disclosures that Cogent had more installation capacity than ready orders, the discontinuation of backlog reporting in February 2026, and further weakness in wavelength revenue and customer connections in May 2026. Cogent common stock fell $6.79, or 29%, to close at $16.37 on May 4, 2026. Hagens Berman also invited people with potentially relevant non-public information to consider the SEC Whistleblower program.