Nike shares closed up 4.64 percent after Tim Cook and Robert Swan purchased nearly $3.5 million in stock to signal confidence in the company.The significant investment by Cook, who serves as the lead independent director, doubles his stake as Elliott Hill implements a "win now" strategy to reverse declining sales.Despite the recent recovery, the footwear giant faces an 18.5 percent decline this year following weak quarterly results in China and potential tariff impacts on pricing.