** TD Cowen expects US semiconductor companies' quarterly earnings to be 'fine on paper' and annual outlook from cos to be a 'wild card' given potential pressure on margins and revenue from tariffs

** Nvidia NVDA.O remains brokerage's top pick; it also prefers AMD AMD.O, Broadcom AVGO.O and Credo CRDO.O

** Nvidia shares flat in premarket trading

** AMD and Broadcom down between 1% and 1.5%; Credo falls ~5%

** Trump's "reciprocal" tariffs on dozens of countries took effect on Wednesday, including a 104% duty on Chinese goods

** "Tariffs throw a significant wrench into what was already likely a volatile set of earnings" - TD Cowen

** NVDA and AMD set to report quarterly results on May 28 and May 6 respectively

** The Philadelphia Semiconductor index .SOX has dropped 17% since 31 March, taking losses so far this year to 28.5%

** Brokerage cuts PTs of following semiconductor stocks:

(Reporting by Rashika Singh in Bengaluru)

((Rashika.Singh@thomsonreuters.com;))