Walmart dumped its stake in the Chinese e-commerce company.Shares of JD.com (JD -5.30%) were falling today on news that Walmart (WMT 0.59%) had dumped its stake in the Chinese e-commerce company, according to a Securities and Exchange Commission filing this morning. JD and Walmart had been seen as partners at one point in China, but the stock sale seems to indicate that Walmart has soured on the relationship, especially after JD.com stock has underperformed for the last few years.As of 11:38 a.m. ET on Wedn ...