Bill Ackman’s Pershing Square Capital Management has built a stake in Nike Inc. (NKE.N), according to a person familiar with the matter.

Unlike Pershing Square’s activist campaigns, in which it pressures company executives or directors to make changes, its investment in the sportswear company is passive, said the person, who asked not to be identified because the details are private.

A representative for Beaverton, Oregon-based Nike didn’t immediately respond to a request for comment. Nike shares have risen more than 30 per cent since the end of September, valuing the company at US$110 billion.

Faced with shrinking assets, Ackman is cutting 10 employees from the firm, a person familiar with that matter said this week. The firm now oversees about US$9 billion in assets, less than half of its 2015 peak.

Ackman’s Nike investment was reported earlier by Reuters.

With assistance from Matt Townsend