After doubling in stock price within the year, Valero Energy (VLO.US) and Marathon Petroleum (MPC.US) were downgraded by Jefferies: valuations are already elevated.

Zhito Finance APP has learned that Jefferies downgraded refiners Valero Energy (VLO.US) and Marathon Petroleum (MPC.US) from "Buy" to "Hold," with target prices of $401 and $413, respectively, saying that after the two companies' share prices more than doubled over the past year, their valuations now appear elevated.