Leading stocks, led by Monster Beverage’s monster gains, held their highs throughout the session despite a volatile market that ended mixed. Monster (MNST) gapped up and rocketed 21.84, or 31%, to 93.49 in monster volume, shooting past a 75.73 buy point. The energy drink maker late Thursday announced a partnership deal with Coca-Cola (KO), in which the soft-drink giant will buy a 16.7% stake in Monster for $2.15 billion.