Mid-Morning Market Update: Markets Open Lower; Staples Posts Downbeat Earnings By: Benzinga via Benzinga May 20, 2014 at 10:52 AM EDT Following the market opening Tuesday, the Dow traded down 0.40 percent to 16,445.69 while the NASDAQ tumbled 0.51 percent to ... Read More >> Related Stocks: Dick's Sporting Goods Inc Oneok Inc Ophthotech Corp Red Robin Gourmet Burgers Inc Staples Urban Outfitters