Earnings in the hard-hit retail sector kick off this week. And Walmart, Macy's and Canada Goose are among the names set to report. Escalating trade tensions between the U.S. and China and the potential impact on retail companies have dragged the sector lower. As of Monday, the SPDR Retail ETF dropped about 7.5% in the previous two weeks — hitting its lowest level of 2019. However, history says a rebound could be ahead.