Zacks Investment Research lowered shares of National Oilwell Varco from a "hold" rating to a "sell" rating in a report on Tuesday, April 18th. (NYSE: NOV ). Tompkins, New York-based fund reported 450 shares. Cowen & Co maintained National-Oilwell Varco, Inc. Product Partners Lc invested in 0.58% or 237,000 shares.