ADTN Investor Alert: Levi & Korsinsky Notifies Investors of Investigation Into ADTRAN Holdings (ADTN) businesswire.com July 28, 2026 at 9:09 AM ET ADTN The article announces an investigation into ADTRAN Holdings by Levi & Korsinsky, LLP. This is a legal matter and does not directly reflect on the company's operational performance or future prospects.