Bill Ackman's protege has a new target - and its shares are popping

Shares in Deckers Outdoor have soared after an activist hedge fund took a stake in the company.

Marcato Capital Management announced a 6% stake in the company earlier on Wednesday in a 13-D filing. Deckers is up nearly 9% Wednesday as of 3:35 p.m. Eastern.

Marcato is led by Mick McGuire, who has been called a Bill Ackman "protégé."

Earlier this week, it nominated four directors to serve on the board of Buffalo Wild Wings, officially launching a proxy fight against the US restaurant chain.

Marcato managed $1.5 billion as of midyear last year, according to the Hedge Fund Intelligence Billion Dollar Club ranking.