The Vanguard Group, Inc. is an American registered investment adviser founded on May 1, 1975, and based in Malvern, Pennsylvania, with approximately $12 trillion in global assets under management as of 2025. It is the largest provider of mutual funds and the second-largest provider of exchange-traded funds (ETFs) in the world after BlackRock's iShares. In addition to mutual funds and ETFs, Vanguard offers brokerage services, educational account services, financial planning, asset management, and trust services. Several mutual funds managed by Vanguard are ranked at the top of the list of mutual funds in the United States by assets under management. Along with BlackRock and State Street, Vanguard is considered to be one of the Big Three index fund managers.

Founder and former chairman John C. Bogle is credited with the creation of the first index fund available to individual investors and was a proponent and major enabler of low-cost investing by individuals, though Rex Sinquefield has also been credited with the first index fund a few years before Bogle.

Vanguard is owned by the funds managed by the company and is therefore owned by its customers. Vanguard offers two classes of most of its funds: investor shares and admiral shares. Admiral shares have slightly lower expense ratios but require a higher minimum investment, often between $3,000 and $100,000 per fund. Vanguard's corporate headquarters is in Malvern, a suburb of Philadelphia, Pennsylvania. It has satellite offices in Charlotte, North Carolina, Dallas, Texas, Washington D.C., and Scottsdale, Arizona, as well as Canada, Australia, Asia, and Europe.

In 1951, for his undergraduate thesis at Princeton University, John C. Bogle conducted a study in which he found that most mutual funds did not earn more money compared to broad stock market indexes. Even if the stocks in the funds beat the benchmark index, management fees reduced the returns to investors below the returns of the benchmark.

Immediately after graduating from Princeton University in 1951, Bogle was hired by Wellington Management Company. In 1966, he forged a merger with a fund management group based in Boston. He became president in 1967 and CEO in 1970. However, the merger ended badly and Bogle was therefore fired in 1974. Bogle has said about being fired: "The great thing about that mistake, which was shameful and inexcusable and a reflection of immaturity and confidence beyond what the facts justified, was that I learned a lot. And if I had not been fired then, there would not have been a Vanguard."

Bogle arranged to start a new fund division at Wellington. He named it Vanguard, after Horatio Nelson's flagship at the Battle of the Nile, HMS Vanguard. Bogle chose this name after a dealer in antique prints left him a book about Great Britain's naval achievements that featured HMS Vanguard. Wellington executives initially resisted the name, but narrowly approved it after Bogle mentioned that Vanguard funds would be listed alphabetically next to Wellington Funds.

The Wellington executives prohibited the fund from engaging in advisory or fund management services. Bogle saw this as an opportunity to start a passive fund tied to the performance of the S&P 500, which was established in 1957. Bogle was also inspired by Paul Samuelson, an economist who later won the Nobel Memorial Prize in Economic Sciences, who wrote in an August 1976 column in Newsweek that retail investors needed an opportunity to invest in stock market indexes such as the S&P 500.

In 1976, after getting approval from the board of directors of Wellington, Bogle established the First Index Investment Trust (now called the Vanguard 500 Index Fund). This was one of the earliest passive investing index funds, preceded a few years earlier by a handful of others (e.g., Jeremy Grantham's Batterymarch Financial Management in Boston, and index funds managed by Rex Sinquefield at American National Bank in Chicago, and John "Mac" McQuown at Wells Fargo's San Francisco office).