What is a mutual fund?
A plain-English guide to one of the oldest and most common ways to invest.
By Kenny Goodrich, Founder of Money Masters MediaMutual funds are how a great many people first invest, often through a workplace retirement plan without thinking much about the name. A mutual fund pools money from many investors and uses it to buy a professionally managed basket of investments, such as stocks or bonds. They are close relatives of index funds and ETFs. This guide explains what mutual funds are, how they work, how they compare to ETFs and individual stocks, the difference between active and index versions, and how investors use them in a diversified portfolio.
What is a mutual fund?
A mutual fund is a pool of money gathered from many investors and invested together in a single basket of assets. When you buy into the fund, you own a share of that whole basket rather than any one investment inside it. A professional manager or team is responsible for what the fund holds.
The appeal is that one purchase can give you a broad, ready-made mix that would be hard to build on your own. Many mutual funds are also index funds, built to track a market index at low cost rather than to beat it.
How mutual funds work
When you invest in a mutual fund, your money is combined with everyone else who owns it, and the fund uses the pool to buy its holdings. You receive shares of the fund that represent your slice of the whole basket.
Unlike a stock, a mutual fund does not trade all day long. Its price, called the net asset value or NAV, is calculated once a day after the market closes, based on the value of everything it holds. Any buying or selling you do that day happens at that single daily price, directly with the fund company rather than on an exchange.
Mutual funds vs ETFs
Mutual funds and ETFs are close cousins. Both are baskets of investments, and many hold nearly identical things. The main differences come down to how and when you trade them.
Mutual funds
Priced once a day, after the market closes, and bought directly from the fund company. Some carry minimum investments or sales charges, though many are low cost. They have been a retirement-account staple for decades.
ETFs
Trade on an exchange throughout the day at a live price, like a stock. They often have low expense ratios and no minimum beyond the price of one share. A newer wrapper around a similar idea.
Neither wrapper is automatically better. For a fuller look at the exchange-traded side, see What Is an ETF?. What matters most is what is inside and what it costs.
Mutual funds vs individual stocks
It also helps to see how a mutual fund compares to buying a single company. The difference comes down to diversification.
Buying a mutual fund
One purchase spreads your money across everything the fund holds, often hundreds of companies, with a professional handling the details. You give up the chance of a single big winner.
Buying a single stock
You own one company directly. The reward for being right is larger, but so is the damage if it stumbles, and choosing well year after year is genuinely hard.
Active mutual funds vs index mutual funds
Mutual funds come in two broad styles, and the difference shapes both the cost and what you are paying for.
Active funds
A manager and team try to beat the market by choosing what to hold. That effort costs more in fees, and beating the market consistently over long periods has proven difficult.
Index funds
Simply track a market index and aim to match it at a low cost. There is no manager trying to outguess the market, which keeps fees down and the holdings predictable.
The index a fund follows decides what it actually owns. To see how the major lists differ, read Stock Market Indexes Explained.
Common types of mutual funds
Mutual funds are grouped by what they hold. A few broad categories cover most of what beginners will meet.
Stock funds
Hold a basket of stocks, from broad market funds to ones focused on a region, size, or sector. Built for growth, with the swings that come with it.
Bond funds
Hold a basket of bonds and aim for steadier income. Many investors use them to balance out the bumpier stock portion of a portfolio.
Balanced and target-date funds
Hold a mix of stocks and bonds in one fund. Target-date funds gradually shift toward safer holdings as a chosen retirement year approaches.
Money market funds
Hold very short-term, high-quality debt and aim to stay stable. Often used as a place to park cash, with modest expected returns.
Target-date funds are a popular one-stop option, since a single fund holds a diversified mix and adjusts it over time. How that mix is chosen is the subject of Asset Allocation Basics.
Costs and fees
Costs matter more with mutual funds than many beginners expect, because they are charged every year and quietly compound against you. The main one is the expense ratio, an annual fee taken as a percentage of what you have invested. Broad index funds tend to be very cheap, while active funds usually charge more for the manager and team.
Some funds also carry a load, which is a one-time sales charge when you buy or sell, and a few add ongoing marketing fees. Plenty of low-cost, no-load funds avoid these extras entirely. For a closer look at how small fees add up over time, see Index Fund Investing.
Why investors use mutual funds
For all the attention ETFs get, mutual funds remain a cornerstone of investing, especially in retirement accounts. A few strengths explain why. Above all, a single fund delivers ready-made diversification.
Built-in diversification
A single fund can hold hundreds of securities, so one purchase spreads your money far more widely than most people could on their own.
Professional management
A team handles the buying, selling, and record keeping. For people who would rather not manage it all themselves, that convenience is the main draw.
Easy to automate
Mutual funds are built for steady, automatic investing, which is why they are so common inside workplace retirement plans.
Their built-in automation pairs naturally with dollar cost averaging, which is how most workplace retirement contributions already work.
Risks of mutual fund investing
A mutual fund is a convenient wrapper, but it does not change the basic truth that investing carries risk. The relationship between risk and reward applies here just as it does anywhere else.
Market risk remains
A fund rises and falls with whatever it holds. A stock fund still drops when the market drops. Pooling money spreads risk, it does not remove it.
Fees drag on returns
Higher-cost funds, especially active ones with sales charges, take a bigger bite each year. Over decades, that gap can add up to a meaningful amount.
Beating the market is hard
Many active funds fail to outperform a simple index over the long run, so paying more does not reliably buy better results.
Because a broad stock fund moves with the whole market, the wider backdrop matters. Tools like the Economic Outlook Tracker are for understanding that context, not for timing trades.
What beginners should understand
Mutual funds are a useful and familiar tool, but a few honest points make them easier to use well.
Look at what it holds and costs
Two funds with similar names can behave very differently. What is inside the fund and what it charges matter far more than the label.
Watch for sales charges
Some funds carry a load, a one-time sales charge, on top of the annual expense ratio. Many low-cost no-load funds avoid it entirely.
They reward patience
Mutual funds are built for long holding periods. Frequent switching tends to add costs and taxes without improving results.
Frequently asked questions
What is a mutual fund?
A mutual fund pools money from many investors and uses it to buy a professionally managed basket of investments, such as stocks or bonds. When you buy into the fund, you own a share of the whole basket rather than any single investment inside it. One purchase can give you a broad, ready-made mix that would be hard to build on your own.
How is a mutual fund different from an ETF?
Both are baskets of investments, and many hold nearly identical things. The main difference is how they trade: a mutual fund is priced once a day after the market closes and bought from the fund company, while an ETF trades on an exchange throughout the day like a stock. Neither wrapper is automatically better, and what matters most is what the fund holds and what it costs.
What is the difference between an active fund and an index fund?
An active fund has a manager and team trying to outperform the market by choosing what to hold, which costs more in fees. An index fund simply tracks a market index and aims to match it at a low cost, with no manager trying to outguess the market. Many active funds fail to outperform a simple index over the long run, so paying more does not reliably buy better results.
What fees do mutual funds charge?
The main fee is the expense ratio, an annual charge taken as a percentage of what you have invested. Broad index funds tend to be very cheap, while active funds usually charge more. Some funds also carry a load, a one-time sales charge when you buy or sell, though plenty of low-cost no-load funds avoid it entirely.
Are mutual funds a safe investment?
A mutual fund spreads your money across many holdings, but it does not remove investment risk. A stock fund still falls when the market falls, and higher fees drag on returns over time. Pooling money spreads risk, it does not eliminate it, and you can still lose money you put in.
How this connects to Money Masters tools
Mutual funds hold pieces of the market, so it helps to understand the indexes and the economy behind them. These free Money Masters tools and guides break it down in plain English. Start with the Dashboard to see markets and the economy on one screen.
Know what you own
Mutual funds make it simple to own a diversified slice of the market, but the costs and contents are what decide your results. These free tools and guides track the market, rates, and the economy together, with no jargon and no hype.
Educational content only: This guide is for education and general information, not financial, investment, or tax advice, and not a recommendation to buy or sell any security, fund, or mutual fund, or to follow any particular investing strategy. Investing carries risk, including the possible loss of money you put in. Always do your own research and consider speaking with a licensed financial professional before making decisions.
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