Changing the way millennials buy fashion, Luke Grana, successfully built and sold several companies before founding the e-commerce site Grana. A celebrity endorsing sensation -- notably American actress Jessica Alba --, Grana is not a fashion business, but rather a start-up aimed at selling sustainably sourced, affordable and high-quality clothing. Essentially an online store, it also operates temporary pop-up stores in four countries. Run on a lean business model that has cut out the distributors, middleman and warehouses, Grana is running on a 15 percent month-to-month expansion rate and has received significant funding from Alibaba.

Armed with a global vision, Luke is working to expand the reach of Grana beyond just the 12 countries it currently ships to. In particular, he is focused on the U.S. market, where he is planning to open Grana flagship store in Soho, New York.