The preliminary figures released in a Form 8-K reveal revenue between $280 million and $282 million, missing the company’s previous guidance of $283 million to $303 million. Profitability also took a hit, with non-GAAP operating margins expected between 3.5% and 4.0%, significantly lower than the projected 5% to 9%.

Levi & Korsinsky is now scrutinizing whether ADTRAN provided adequate warning regarding its customer concentration and the potential risks inherent in its project timelines. Given that one customer previously accounted for over 10% of total revenue as of late 2025, investigators are assessing if the company failed to properly inform shareholders about the vulnerabilities associated with this specific dependency. Investors who incurred losses are currently being encouraged to submit their trade records for an evaluation of potential recovery options.