Candy Crush Saga maker King down over 15 percent following stock IPO

King ended its first day of trading down 15.56 percent from its opening value. That's the worst first-day performance for a major US IPO in the last 15 years, according to an analysis by Rennaisance Capital.

But the company has yet to diversify its revenue away from the breakout hit of Candy Crush, which represented a full 78 percent of King's gross bookings in the last quarter of 2013, despite heavy efforts to promote other titles through TV advertising and other means.