Ciena Co. (NYSE:CIEN – Get Rating)’s stock price gapped down prior to trading on Thursday . The stock had previously closed at $51.86, but opened at $48.53. Ciena shares last traded at $49.66, with a volume of 2,004,963 shares traded. Analyst Upgrades and Downgrades A number of research firms recently weighed in on CIEN. Cowen […]