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Mutual funds
Since 1924· Asset or instrument
Fact, law or dataA rule, statute, definition or measured number.
A mutual fund pools many investors' money into one professionally managed portfolio, bought and sold once a day at its net asset value.
See it on the Money & Finance map →How it works
The first US open-end fund, Massachusetts Investors Trust, opened in Boston in March 1924. The Investment Company Act of 1940 set the rules: redemption at net asset value, independent directors, disclosure. Investors pay an expense ratio and sometimes sales charges ('loads') or marketing fees. Funds can be actively managed or track an index. Over 15 years about 9 in 10 active large-company funds trail the S&P 500. They remain the core of most 401(k) plans, though ETFs are drawing money away.
Why it matters
They gave ordinary savers cheap diversification and professional management, making stock and bond investing a mass habit after World War II.
Think of it like
Like a real estate syndication pooling many investors under one sponsor, except you can cash out any business day at that day's value.
Facts, rules and data
SEC registration and prospectuses; Investment Company Institute data on assets; S&P's SPIVA scorecards comparing active funds with their benchmarks.
Debates and risks
Why investors kept trillions in higher-fee active funds despite decades of evidence they trail cheaper index funds after costs.
Connections (2)
▸John Bogle and Vanguard criticized the high fees of Mutual fundsFact, law or data
The connection
Bogle argued that fund managers as a group cannot beat the market, so costs largely decide what investors earn. He attacked high fees, sales charges, heavy trading and fund companies run for outside owners. Vanguard's price cuts pushed rivals: average stock fund fees fell from about 1% in 1996 to about 0.4% by 2024.
When and why
In speeches, Senate testimony after the 2003 fund-trading scandal, and books such as Common Sense on Mutual Funds (1999).
How we know
Investment Company Institute data show the long fall in asset-weighted fees; Morningstar studies find low fees the most dependable predictor of better fund results.
Debates and risks
How much of the fee decline came from Bogle and Vanguard's competition versus 401(k) scrutiny, ETFs and other forces is hard to separate.
▸Index funds and passive investing began as a type of Mutual fundsFact, law or data
The connection
The first public index fund was a mutual fund: investors bought shares directly from the fund company at the end-of-day price, like any other mutual fund. Indexing simply replaced the stock picker with a rule. Index mutual funds still hold trillions, though ETFs now draw much of the new money.
When and why
Vanguard's 1976 fund; mutual funds themselves date back to the Massachusetts Investors Trust in 1924.
How we know
Fund registrations under the Investment Company Act of 1940 and prospectuses; Morningstar and ICI track index mutual fund assets.
Debates and risks
Whether index mutual funds keep their place as ETFs, with their tax advantages and intraday trading, take most new money, especially in taxable accounts.