Groupon (GRPN -5.9%) dives below $8 for the first time after Citi's Mark Mahaney cuts his...

Groupon (GRPN -5.9%) dives below $8 for the first time after Citi's Mark Mahaney cuts his estimates on concerns about European sales, which account for 25% of Groupon's revenue. Mahaney now expects Groupon to post 2013 EBITDA of $718M, down from a prior $930M. The company's Q2 report is expected to arrive around month's end. (previous)