A mutual fund is a pooled investment that collects money from many investors and uses it to buy a diversified portfolio of stocks, bonds, or other assets, managed by a professional fund manager (or, for index funds, run by rules rather than a person). When you buy a share of a mutual fund, you own a proportional slice of everything the fund holds. This guide explains how mutual funds work, what they cost, and how they compare to ETFs.
This article is educational only and is not personalized financial advice. Fund performance and fees vary widely — always review a fund’s prospectus before investing.
In Plain English
- A mutual fund pools money from many investors to buy a diversified basket of investments in one purchase.
- Funds are either “actively managed” (a manager picks holdings, trying to beat the market) or “passively managed” (the fund simply tracks an index) — passive funds typically charge much lower fees.
- Mutual funds trade once per day at a single price, unlike ETFs, which trade throughout the day like a stock.
How Mutual Funds Work
You buy mutual fund shares directly from the fund company (like Vanguard or Fidelity) or through a brokerage account. Unlike a stock or ETF, mutual fund shares aren’t priced continuously throughout the trading day — they’re priced once, after market close, based on the Net Asset Value (NAV): the total value of everything the fund holds, divided by the number of shares outstanding. Every buy or sell order placed during the day executes at that end-of-day NAV.
Active vs Passive Mutual Funds
| Type | How It’s Run | Typical Fees |
|---|---|---|
| Actively managed | A manager or team selects holdings, aiming to beat a benchmark index | Higher — commonly 0.5%–1.5%+ expense ratio |
| Passively managed (index fund) | Tracks a benchmark index by rule, no manager stock-picking | Much lower — often under 0.10% |
Decades of independent research, including S&P’s SPIVA scorecards, have consistently found that most actively managed funds underperform their benchmark index over long periods, after fees. That doesn’t mean no active fund ever outperforms — some do, in some years — but consistently identifying which ones will in advance is difficult, which is why low-cost passive index funds have grown so popular with long-term investors. See our what is an index fund and best index funds for beginners guides for more.
Fees to Watch For
- Expense ratio — an annual fee, expressed as a percentage of your investment, charged regardless of performance.
- Load fees — a sales charge some funds add when you buy (“front-load”) or sell (“back-load”) shares. Many modern funds, especially from providers like Vanguard and Fidelity, are “no-load.”
- Minimum investments — many mutual funds require an initial minimum purchase (commonly a few hundred to a few thousand dollars), unlike most ETFs, which you can buy one share at a time.
Mutual Funds vs ETFs
Both pool money into a diversified basket, but they differ in structure:
- Trading: ETFs trade all day on an exchange at fluctuating prices; mutual funds trade once daily at the closing NAV.
- Minimums: ETFs can often be bought one share (or even a fraction) at a time; many mutual funds require a set minimum investment.
- Tax efficiency: ETFs are generally more tax-efficient in taxable accounts due to their structure, though this varies by fund.
- Cost: Both come in low-cost index versions and higher-cost active versions — the fund’s management style matters more than the wrapper (ETF vs mutual fund) alone.
For a full breakdown, see our dedicated ETFs vs mutual funds comparison.
Common Beginner Mistakes
- Chasing a fund’s recent top performance. Past returns don’t predict future results, and today’s top performer is often tomorrow’s laggard.
- Ignoring the expense ratio. A 1% annual fee sounds small but compounds into a large cost over decades.
- Not checking for load fees. A 5% front-load fee is a real, immediate cost before your money is even invested.
- Assuming all mutual funds are actively managed. Many of the largest, cheapest funds available are actually passive index funds.
The Bottom Line
Mutual funds remain one of the simplest ways to buy a diversified portfolio in a single purchase, whether through an employer retirement plan or a brokerage account. The details that matter most are whether the fund is active or passive, what it charges in fees, and whether a minimum investment or load fee applies — not the mutual fund wrapper itself.
This article is educational only and does not constitute financial or investment advice. All investing involves risk, including the possible loss of principal. Always review a fund’s prospectus and consider speaking with a licensed financial professional.
Frequently Asked Questions
Are mutual funds safer than stocks?
A mutual fund’s diversification can reduce single-company risk compared to holding one stock, but the fund still carries market risk — a stock mutual fund will still fall when the broader market falls. Diversification manages risk; it doesn’t eliminate it.
What is a good expense ratio for a mutual fund?
For passive index funds, expense ratios under 0.10% are common and considered low-cost. For actively managed funds, ratios are typically higher; whether the extra cost is worth it depends on whether the fund’s performance justifies it, which is difficult to know in advance.
Can I lose money in a mutual fund?
Yes. Mutual funds are not FDIC-insured and their value fluctuates with the underlying holdings. Bond funds and money market funds are generally lower-risk than stock funds, but no mutual fund guarantees against loss.
Do I need a lot of money to start investing in mutual funds?
It depends on the fund — some require a minimum initial investment (commonly a few hundred to a few thousand dollars), though many retirement plans allow smaller ongoing contributions. Check each fund’s specific minimum before investing. The SEC’s Investor.gov has a general primer on mutual fund basics.
This article is for educational purposes only and does not constitute financial or investment advice. Investing involves risk, including the possible loss of principal. Always do your own research, and consider speaking with a licensed financial professional before making investment decisions.
Izhaq Shah is the founder of GetIntoMarkets. He holds a Master’s in Finance and Commerce, with over 10 years in the financial industry and 15 years of writing experience. He makes investing in stocks, ETFs and crypto simple and practical for everyday people building wealth with confidence.