Alibaba Group Holding Ltd.'s stock slipped 0.5% in afternoon trade Thursday, paring earlier gains of as much as 1.2%, as investors prepare for the China-based e-commerce giant's fiscal fourth-quarter results, due out before Friday's open. Wall Street oddsmakers are ready for a big one-day, post-earnings move in the stock, as those who buy an options strategy known as a straddle won't start making money unless the stock moves more than 5.0% in either direction on Friday. That's more than the average post-earnings move of 4.2% (media is 4.0%) the day after the past 14 quarterly reports, since Alibaba went public in September 2014. The stock has lost 3.5% over the past three months, while the S&P 500 has shed 4.6%.