In afternoon trading on Thursday, Energy stocks are the worst performing sector, showing a 2.0% loss. Within that group, Diamondback Energy, Inc. (Symbol: FANG) and ONEOK Inc (Symbol: OKE) are two large stocks that are lagging, showing a loss of 6.0% and 5.4%, respectively. Among energy ETFs, one ETF following the sector is the Energy Select Sector SPDR ETF (Symbol: XLE), which is down 1.7% on the day, and up 4.77% year-to-date. Diamondback Energy, Inc., meanwhile, is up 14.21% year-to-date, and ONEOK Inc i ...