Why struggle to find a needle in a haystack when you can buy the haystack? That was Vanguard founder Jack Bogle‘s argument for indexing nearly half a century ago when he launched the first index fund for individual investors. The investment approach was easy to execute and offered instant diversification, all for a low fee. And as it turns out, returns have been tough to beat.

Index mutual funds and exchange-traded funds (ETFs) have done better, on average, than most actively managed funds for years. The Vanguard 500 Index Fund (VOO), which mirrors the S&P 500 Index, has outpaced 90% of similar U.S. stock funds over the past 15 years, according to Morningstar.