Jack Bogle, often referred to as the \u2018King\u2019 of index funds, died on 16 January, a little over three months short of his 90th birthday.\u00a0Such is the great man\u2019s repute that even Warren Buffett wrote in his praise recently, \u201cIf a statue is ever erected to honor the person who has done the most for American investors, the hands down choice should be Jack Bogle." We take a look closer look at Jack Bogle's contribution to the global mutual fund industry. Pioneering low-cost investing Jack Bogle had based the concept of index fund investing on the premise that, in the long-term, it would not be possible to achieve returns superior than the market, after taking into account the costs associated with actively managed funds. His idea was that instead of trying to beat the market and charging high costs, the index fund would mimic the index performance over the long run \u2014 thus achieving higher returns with lower costs. The Vanguard Group, the firm Jack Bogle started\u00a0in 1975 now has 190 funds and about $5.3 trillion in assets, and an average expense ratio of 0.11%. \u201cFor decades, Jack has urged investors to invest in ultra-low-cost index funds. In his crusade, he amassed only a tiny percentage of the wealth that has typically flowed to managers who have promised their investors large rewards while delivering them nothing \u2013 or, as in our bet, less than nothing \u2013 of added value,\u201d Warren Buffett had written in a letter to shareholders. Also read:\u00a0Wipro Q3 net profit up 32% on-year; announces 1:3 bonus issue Jack Bogle is often quoted as saying, \u201cFund investors are confident that they can easily select superior fund managers. They are wrong.\u201d\u00a0 Warren Buffett\u2019s had once estimated that investors wasted more than $100 billion on high-fee Wall Street money managers over the past 10 years. "In his early years, Jack was frequently mocked by the investment-management industry. Today, however, he has the satisfaction of knowing that he helped millions of investors realize far better returns on their savings than they otherwise would have earned. He is a hero to them and to me," Warren Buffett had said about Jack Bogle.