Glingener Christoph Officer Transaction

This filing details a transaction by Glingener Christoph, Chief Technology Officer of ADTRAN Holdings, Inc. On August 10, 2026, Christoph acquired 27,924 shares of Common Stock at a price of $0.0 per share. This transaction is coded as 'A' for acquisition. Following this transaction, Christoph directly owns 83,953 shares of ADTRAN Holdings, Inc. common stock. The filing is made on Form 4 and signed by Dan Ragsdale, by power of attorney.