Jefferies analyst Mark Lear upgraded Cimarex Energy (XEC) to Buy from Hold and raised his price target for the shares to $107 from $98. The analyst also downgraded Oasis Petroleum (OAS) to Hold from Buy with an unchanged price target of $14. Infrastructure constraints and wider regional basis have raised growth concerns across the Permian and driven stocks to "irrational valuations," Lear tells investors in a research note. Jefferies also raised its per-barrel Brent price forecast to $77 from $64 in 2018; to $75 from $60 in 2019; and to $70 from $65 in 2020. He notes shares of Cimarex now trade at "more than half a turn discount" to the group on consensus 2018 and 2020 EBITDA. Lear believes Cimarex's recent moves to address gas flow assurance in tandem with strategic partnerships in the Permian "provide some level of relative safety on the company's ability to maintain capital guidance." The analyst cites valuation for his downgrade of Cimarex following the stock's outperformance year-to-date.