Sterne Agee thinks Lululemon is ripping apart at the seams

• Sterne Agee takes a harsh view of Lululemon (NASDAQ:LULU), downgrading the retailer to Underperform from Neutral and slashing its price target to $56.
• The investment firm says channel checks indicate a risk that core LULU customers have been alienated and thinks same-store sales could decelerate in 2014.
• LULU -2.7% premarket.