Shopify (NYSE: SHOP) stock has proven an overwhelming success for early investors, soaring more than fivefold since its IPO in mid-2015. And it's not hard to make the case that the e-commerce platform company is only just getting started. But that also raises the question: Are there any stocks that could potentially put Shopify's returns to shame in the coming years?We asked three top Motley Fool investors to weigh in to that end.