Jack Bogle, Who Revolutionized the Way Millions of Americans Save and Invest, Dies at Age 89 by Pat Regnier John C. Bogle, who founded Vanguard Group and revolutionized the way millions of Americans save and invest, died on Wednesday. He was 89 years old. Bogle’s best-known legacy is the index fund, a low-cost, diversified way to hold stocks or bonds. In an unpredictable market, few investment managers are able to consistently leave their customers, rather than themselves, better off.