Nike Inc. (NKE) shares rose Friday, Jan. 26, after Bill Ackman's Pershing Square Capital Management revealed a stake in the world's biggest sportswear group.

Both The Wall Street Journal and Reuters reported that Ackman's vehicle announced the stake, which was first acquired in October, at an dinner for the fund's investors Thursday evening in New York. However, each report indicated that Ackman is happy to be a passive investor in the Beaverton, Ore-based group as it looks to close the gap on rival Adidas AG (ADDYY) in both domestic and international markets.

Nike shares rose 1% early Friday to $68.32, a move that takes the stock's gains since October to more than 30% and gives it market value of $110 billion.

Adidas shares, by contrast, have fallen 4.5% over that time, thanks in part to a surge in the euro.

Nike has faced a significant challenge from Adidas of late, with the German sportswear giant seeing North American sales top the $1 billion mark over its last fiscal quarter as it continues to steal market share and expand its brand in China.

Adidas said North American sales topped the €1 billion mark for the first time, rising 23% on a currency-neutral basis, a boost that contrasts Nike's 3% fall over the same period to just under $4 billion.

Nike's China's sale grew 9% to $1.108 billion, the company said, but that figure trailed the 28.3% gain for Adidas, which saw total brand sales -- including Adidas and Reebok -- hit €1.102 billion.

More of What's Trending on TheStreet:

More from Markets

Here's What Bankrate's CFA Expects From Interest Rates in 2019

Here's What Bankrate's CFA Expects From Interest Rates in 2019

How Federal Reserve Rate Hikes Will Impact the Economy in 2019

How Federal Reserve Rate Hikes Will Impact the Economy in 2019

How Vulnerable the U.S. Economy Is -- Recession Watch

How Vulnerable the U.S. Economy Is -- Recession Watch

China GDP Slows To Weakest Pace Since 1990 as Trump Trade War Bites Beijing

China GDP Slows To Weakest Pace Since 1990 as Trump Trade War Bites Beijing

Why Bankrate's CFA Expects Two More Rate Hikes in 2019

Why Bankrate's CFA Expects Two More Rate Hikes in 2019