Citigroup sees export supply constraints centered on the Strait of Hormuz as a catalyst for Dow Inc. (DOW), upgrading the stock to buy from neutral. Diane King Hall talks about the firm's recent note, along with Occidental Petroleum's (OXY) double upgrade from Wells Fargo. On the opposite end of the spectrum, she turns to downgrades across the consumer staples sectors from Wells Fargo that target Campbell's (CPB), General Mills (GIS), and Conagra Brands (CAG).