American Express goes down market with Wal-Mart By: MarketWatch October 10, 2012 at 06:00 AM EDT American Express Co. has taken an unexpected down-market turn by creating a card for Wal-Mart Stores Inc. shoppers, writes Carol Kopp. Read More >> Related Stocks: American Express FINANCIAL SEL Green Dot Corp MasterCard Visa Wal-Mart Stores, Inc.