So far in 2018, Oasis Petroleum (OAS) is the fifth-best-performing upstream stock from the US. Oasis Petroleum primarily operates in the Williston Basin in the US. Year-to-date in 2018, OAS rose ~49% from its 2017 close of $8.41 to $12.52. Oasis Petroleum has easily outperformed the SPDR S&P Oil and Gas Exploration & Production ETF (XOP) in 2018. XOP is up ~16% in 2018. OAS is also outperforming crude oil (USO) and natural gas (UNG). In 2018, so far, crude oil is up ~19%, whereas natural gas is down ~2%.