Argus Downgrades Adtran After 'Weak' Q1 By: Benzinga via Benzinga April 19, 2018 at 14:40 PM EDT Telecom equipment provider ADTRAN, Inc. (NASDAQ: ADTN) issued a "weak" guidance first-quarter printTuesday, according to ... Read More >> Related Stocks: Adtran Holdings Inc CenturyLink