These investments have squeezed profits, but the firm is banking on growth. Walmart’s leaders aim to prove that an old-fashioned retailer can continue to dominate in the age of e-commerce. Walmart may show how to merge physical and online retail. It is sure to boast of its progress at its annual meeting on June 3rd: it was one of the few American retailers to post cheering first-quarter results in May. Yet its reign as undisputed retail champion is over.