Key Takeaways Nike shares slumped Friday after the athletic apparel giant gave a weaker-than-expected outlook and warned of sales headwinds in China.The shoe maker's fiscal second-quarter revenue and earnings beat analysts' estimates as sales in North America rose, but sales in China sank. Nike shares tumbled Friday, despite quarterly profits that topped estimates, as a weaker-than-expected outlook and headwinds in China weighed on sentiment. The shares were down nearly 10% to about $59 in recent tradi ...