Stifel Warns Twitter May Go Way Of Tech Busts, Cuts To Sell By: TalkMarkets February 02, 2016 at 13:10 PM EST Stifel analyst Scott Devitt downgraded Twitter to Sell form Hold, saying that it has "never fully developed into a sustainable public company. Read More >> Related Stocks: Groupon Cl A Twitter, Inc. Yahoo Zynga Inc Cl A