A mutual fund pools money from many investors and uses it to buy a collection of investments. A fund might own stocks, bonds, cash-like instruments, or some combination of all three. Instead of choosing every investment yourself, you buy shares of the fund and get a slice of whatever it holds.
Why People Use Mutual Funds
One appeal is simplicity. Buy into a mutual fund, and you instantly own a small piece of every investment in it, which might be hundreds of individual stocks or bonds. You don’t have to pick each one.
They show up in a lot of places:
- 401k plans
- 403b plans
- IRAs
- Roth IRAs
- Brokerage accounts
Some funds are broad and diversified. Others are narrow, focused on one sector, country, or strategy. A “target-date fund” is a common type in retirement accounts, it automatically shifts its stock and bond mix as you get closer to retirement, so you don’t have to manage the balance yourself.
Active vs Passive Funds
An actively managed fund has managers trying to pick investments that will outperform a benchmark. They research companies, study trends, and make buy-and-sell decisions. You’re paying for that expertise and hoping it delivers.
A passively managed fund usually tracks an index, a predefined basket of investments that measures part of a market. Index funds are the most common type of passive fund. The fund simply holds the same investments as the index it tracks, in the same proportions, without a team of analysts second-guessing each choice.
Active funds often cost more. Higher cost doesn’t guarantee better results. Research consistently shows that most actively managed funds underperform their benchmark after fees over long periods. See What Is An Index Fund? for more on how passive funds work.
Fees Matter
Common costs include:
- Expense ratio: the annual percentage taken from your investment to cover management and operating costs; this is the main ongoing cost
- Sales loads: front-end loads charge a percentage when you buy; back-end (or deferred) loads charge when you sell; many mutual funds today are “no-load”
- Transaction fees: some brokerages charge a fee to buy certain mutual funds
- Account fees: some funds or platforms charge annual or maintenance fees
- Tax costs in taxable accounts: actively managed funds trade more frequently, which can trigger taxable capital gains distributions even if you didn’t sell anything
Even small fee differences add up. A 1% annual fee sounds modest, but over 30 years it can eat a significant portion of your gains. The same compounding math that grows your money also compounds the drag of fees. See How Compound Interest Works for a concrete illustration.
Mutual Fund vs ETF
| Mutual Fund | ETF | |
|---|---|---|
| When it trades | Once per day after market closes | Throughout the trading day |
| Minimum investment | Often $500–$3,000 | Usually one share (often under $100) |
| Automatic investing | Easy, just set a dollar amount | Harder, must buy whole or fractional shares |
| Tax efficiency in taxable accounts | Less efficient, can have capital gains distributions | Generally more efficient |
| Sales loads | Some funds have loads | Typically no loads |
| Best for | Workplace retirement plans, auto-contributions | Flexibility, low minimums, taxable accounts |
Both can be diversified. Both can lose money. Both require reading what the fund actually owns and what it costs. See What Is An ETF? for more on how the two compare.
Read The Fund Documents
Before investing, read the fund’s basic information: its objective, fees, risks, performance history, and holdings. Every mutual fund is required by law to provide a prospectus covering all of this. A shorter “summary prospectus” is usually available and easier to read.
Don’t choose a fund based only on past performance. Past returns don’t guarantee future results. A fund that did well last year may have been taking on higher risk or benefiting from conditions that won’t repeat.
Frequently Asked Questions
Q: How is a mutual fund different from just buying stocks?
When you buy individual stocks, you’re picking specific companies. If one fails, you take the full loss on that position. A mutual fund spreads your money across many investments automatically, so one company’s failure has a smaller impact on your overall portfolio. You get built-in diversification without having to pick every investment yourself.
Q: Are mutual funds safe?
Mutual funds can still lose value, sometimes significantly. A stock mutual fund will generally rise and fall with the stock market. A bond mutual fund can lose value when interest rates rise. How “safe” a fund is depends heavily on what it holds and your time horizon. For more context, see What Is Investment Risk?.
Q: What is an expense ratio?
The expense ratio is the annual percentage of your investment that the fund charges to operate. A 0.10% expense ratio on a $10,000 investment costs you $10 per year. A 1.0% expense ratio on the same amount costs $100. That difference compounds over decades into a meaningful gap in your final balance.
Q: Should I pick active or passive mutual funds?
For most long-term investors, low-cost passive index funds tend to produce better results after fees than actively managed funds. That said, workplace retirement plans sometimes offer a limited menu. In that case, pick the broadest, lowest-cost options available.
Learn More
- Investor.gov: Mutual Funds
- SEC.gov: Mutual Funds, A Guide for Investors
- SEC: Understanding your investment options