ADTRAN Holdings, Inc. (NASDAQ: ADTN and FSE: QH9) disclosed preliminary unaudited revenue, alongside GAAP and non-GAAP operating margin, for the quarter and year ending December 31, 2025, in Huntsville, Ala. The company's announcement was prompted by German ad hoc disclosure regulations in light of anticipated results exceeding previously projected revenue guidance. Key financial metrics were made public due to this anticipated outperformance.