Analysts’ downgrades for Friday, May 20th: AudioCodes (NASDAQ:AUDC) was downgraded by analysts at StockNews.com from a strong-buy rating to a buy rating. CECO Environmental (NASDAQ:CECE) was downgraded by analysts at StockNews.com from a buy rating to a hold rating. Columbia Banking System (NASDAQ:COLB) was downgraded by analysts at Zacks Investment Research from a buy rating […]