Like Costco Wholesale (COST) and Chipotle Mexican Grill (CMG), Starbucks (SBUX) was recently hit with an E. coli scare. While the coffee giant had to pull its “holiday turkey with stuffing paninis” from West Coast stores as a result, its stock remained relatively unfazed by the outbreak. But selling pressure in the general market now has Starbucks testing support at its 10-week moving average as it works on a new base.