In 2007, Warren Buffett made a famous bet that an unmanaged, low-cost S&P 500 stock index fund (the "S&P") would outperform a group of high-cost, actively managed hedge funds over a ten-year period from 2008 to 2017. The performance would be measured net of fees, costs, and expenses. You can read all about this bet in Berkshire Hathaway’s 2017 shareholder letter, dated February 24, 2018 (https://www.berkshirehathaway.com/letters/2017ltr.pdf).
