John C. Bogle

Indexing. Bogle founded Vanguard in 1975 and launched the first index fund for ordinary investors the next year, built on the argument that, after fees, most active managers trail the market, so the best bet is to own it all cheaply. Vanguard is owned by its funds, which keeps costs down. The idea, mocked at first, now holds a large share of all fund money, raising its own questions about concentrated voting power.