StockX rose in prominence as sneakers became a luxury commodity and the company provided an online home for consumers to buy and sell them, and made a big business out of it. Recently, it announced that it would also sell some of its sneakers with Walmart. “Basketball, and the NBA specifically, is just so synonymous with the StockX customer and products that are in our catalog,” Schwartz said. “Obviously, sneakers being a large part in this first product category, we started with.”