David Schlessinger

Five Below founders David Schlessinger and Thomas Vellios have so far learned to avoid the pitfalls that undid their last business — the bankrupt Zany Brainy toy company. Still, the real test lies ahead. The duo are expanding the chain that sells teens discounted items, from tie-dyed T-shirts to bedazzled iPhone cases, at a breakneck pace, with a 72 percent increase in its store base helping more than double sales in the past two years.