The SEC has widened its probe into B. Riley's financial irregularities and is asking short sellers for additional materials about loans B. Riley may have guaranteed for its former business partner, Brian Kahn. B. Riley's stock dropped more than 50% on Monday after the company suspended its dividend and warned of a share loss for the second quarter. It partly blamed weak consumer spending and a writedown of its stake in Franchise Group. SEC investigators are probing whether B. Riley accurately disclosed risks related to loans to Franchise Group and possible improper insider trading.