Analysts’ upgrades for Wednesday, December 6th: Antero Midstream (NYSE:AM) was upgraded by analysts at StockNews.com from a hold rating to a buy rating. Ardmore Shipping (NYSE:ASC) was upgraded by analysts at StockNews.com from a hold rating to a buy rating. Codexis (NASDAQ:CDXS) was upgraded by analysts at StockNews.com to a sell rating. Chegg (NYSE:CHGG) was […]