Top Wall Street analysts changed their outlook on these top names. For a complete view of all analyst rating changes, including upgrades, downgrades and initiations, please see our analyst ratings page.Deutsche Bank analyst Lee Horowitz upgraded Chewy, Inc. CHWY from Hold to Buy and announced a $45 price target. Chewy shares closed at$35.11 on Wednesday. See how other analysts view this stock.Barclays analyst Luke Sergott upgraded the rating for Thermo Fisher Scientific Inc. TMO from Equal-Weight to Overwe ...