Russ Savage, the founder of Rockstar Energy, said he controls more than 12 million Celsius Holdings shares, a roughly 4.7% stake worth about $300 million, and is pressing for a leadership overhaul after the energy drink maker's second-quarter miss. Savage told CNBC that Celsius should fire its CEO, COO, brand manager and marketing manager and said he is willing to become CEO himself, while Celsius responded that it welcomes potentially value-creating ideas from all shareholders and said board members and executives have engaged with him many times over several years. The campaign followed quarterly revenue of $817.9 million and adjusted diluted EPS of 36 cents, both below expectations, a 15.92% stock drop on Thursday to $24.51, and analyst price-target cuts from Piper Sandler to $36 and Needham to $35 even as both firms maintained bullish ratings. Shares rebounded 11.72% to $26.55 on Friday as investors weighed Savage's activist stake and criticism of the company's execution.