Warren Buffett says most investors should buy an S&P 500 ETF. Here’s why he recommends it

Warren Buffett recommends most investors buy a low-cost S&P 500 ETF, calling it 'the best thing' for most people.

In 2008, Buffett bet $1 million that an S&P 500 fund would beat a group of five hedge funds over 10 years; the S&P 500 generated about 126% total returns versus the funds' average of about 36%.

Since 1919, every 20-year period for the S&P 500 has ended with positive total returns, according to Crestmont Research.

In 2013, Buffett revealed that 90% of the cash bequest for his wife would be invested in an S&P 500 index fund, specifically suggesting Vanguard.