Stocks logged big gains last week following two consecutive weeks of declines. With increases of almost 5%, the Dow Jones Industrial Average (DJINDICES: ^DJI) and the S&P 500 (SNPINDEX: ^GSPC) returned to positive territory for 2018, up roughly 2% each.Earnings season remains in high gear, with hundreds of companies set to announce holiday-quarter results over the next few trading days.