Adidas shares have continued to rise on speculation that a private equity firm could be about to buy a large stake in the sportswear firm. Reports have suggested that Apax Partners could acquire up to 25% of the German firm's shares, although neither Apax nor Adidas have commented on this.
Sportswear firms have been under scrutiny since Puma agreed a $7.1bn (�3.5bn; 5.3bn euros) buyout in April.
Adidas shares gained as much as 2.4% on Wednesday, on top of Tuesday's 3% rise.
One analyst said it was conceivable that a private equity firm could buy into Adidas, given previous deals in the sector.
PPR, which owns Gucci, agreed to buy a 27% stake in Puma, paving the way for a full takeover.
Adidas, itself, bought Reebok for $3.8bn in 2005.