Just to clarify, all index funds are managed by Vanguard, and employees who want to choose their own investment allocation are free to do so. However, for the majority of employees that need help with their investing strategy, we use the same investing principles as Wealthfront and Betterment to make sure they're globally diversified and automatically rebalanced. Also, all funds are held in an SIPC-insured secure trust account by one of the nation's largest third party custodians that deals with billions of dollars -- we never touch the money ourselves.