CELH shares surge 11% after activist Russ Savage takes a $300M stake in Celsius Holdings, demanding executive firings.

Rockstar Energy founder Russ Savage told CNBC he now controls 12 million shares of Celsius Holdings, amounting to roughly 4.7% of the energy drink company.

"Savage said he's offering to take over as CEO before the problems become too deep to fix. When building..."