John Clifton 'Jack' Bogle (1929-05-08 – 2019-01-16) was an American investor, business magnate, philanthropist, and the founder of The Vanguard Group. He revolutionized the investment industry as a pioneering advocate for low-cost index fund investing, creating the first index mutual fund available to individual investors in 1976. Born in Montclair, New Jersey, he graduated from Princeton University in 1951 with an economics degree after writing a thesis on mutual funds. After starting at Wellington Management Company and rising to chairman before being ousted in 1974, Bogle founded Vanguard in 1975 with a unique mutual ownership structure that kept costs low for investors. He served as CEO from 1975 to 1996 and chairman until 1999, growing Vanguard into a trillion-dollar firm. Bogle was a fierce advocate for investor rights, authoring influential books like 'Common Sense on Mutual Funds' and 'The Little Book of Common Sense Investing,' and criticizing Wall Street's excesses. His philosophy emphasized long-term investing, diversification, and minimizing fees. He received numerous accolades including Time magazine's 100 most influential people in 2004, underwent a heart transplant in 1996, and continued writing and speaking until his death at age 89 from complications of stroke and pneumonia in Bryn Mawr, Pennsylvania. His legacy endures in Vanguard's client-owned model and the widespread adoption of passive investing strategies.