Vanguard is one of the world’s largest investment companies, with more than $3 trillion in assets. It is behind three of the top-10 largest exchange traded funds by asset size, including the $47 billion Vanguard FTSE Emerging Markets (VWO) . But the firm is proudest of its achievement as a leader of low-cost investing. Rick Genoni, a Vanguard principal and head of ETF product management, tells IBD about his company’s philosophy and plans.