In the heated battle of robo-advisors vying to help you build a portfolio, Wealthfront and Vanguard Personal Advisor Services are among the top choices. Yet there are key differences — especially the minimum you need to open an account, the types of accounts supported and management fees. Let’s see how they stack up: Wealthfront vs. Vanguard = winner in a given... Kevin Voigt is a writer at NerdWallet.