52-week low for BJ's Restaurants after downgrade

• Shares of BJ's Restaurants (BJRI -4.2%) fall after Oppenheimer moves to a Perform rating after having BJ's set at Outperform.
• BJRI set a new 52-week low of $38.85 in early trading this morning before recovering back to over $41.
• BJ's operating margins and elevated level of buyback activity have been a focus of investors.