Nearly $1 out of every $4 invested went to Vanguard in 2013, which boasted the top three asset-gathering funds, according to Morningstar's 2013 Global Flows Report. The group points to several reasons for Vanguard's success in 2013, such as at-cost pricing. Morningstar also notes that Vanguard's ETFs have taken market share from iShares and State Street.