Wall St lower on bank earnings; Wal-Mart hammered

U.S. stocks retreated on Wednesday as investors absorbed mixed earnings from major banks and Wal-Mart's weak forecast wiped more than $20 billion off the retailer's market value. Weak economic data from the United States and China added to worries about the health of the global economy even as investors' focus shifted to company results. "The major theme, not only today but through the balance of the earnings season, is going to be the revisions to fourth quarter and 2016 earnings," said Bill No