Beginner's Guide · 2026

What Is a Mutual Fund?

A pool of money from thousands of investors, managed by a professional, buying hundreds of stocks or bonds at once. Instant diversification in a single purchase.

$23.9T

Total Assets in U.S.

8,700+

Funds Available

0.015%

Lowest Expense Ratio

01What Is a Mutual Fund?

A mutual fund is an investment vehicle that pools money from many investors to buy a diversified portfolio of stocks, bonds, or other securities. When you invest in a mutual fund, you are buying shares of the fund — and each share represents proportional ownership of everything the fund holds.

Think of it like a potluck dinner. Instead of everyone cooking a full meal, each person brings one dish and everyone shares. A mutual fund works the same way with money: thousands of investors contribute to one fund, and a professional manager invests it across hundreds or thousands of securities. You get diversification that would be nearly impossible to achieve on your own with a small amount of money.

The concept dates back to 1924, when the Massachusetts Investors Trust became the first modern mutual fund. Today, more than 115 million Americans own mutual funds, making them the most popular investment vehicle in the country. Over half of all retirement savings in the U.S. are invested in mutual funds.

The simplest way to think about it:

A mutual fund is a basket of investments managed by a professional. You buy shares of the basket instead of buying individual stocks. One purchase gives you exposure to hundreds of companies.

02How Do Mutual Funds Work?

When you buy shares of a mutual fund, your money goes into a pool with thousands of other investors. A professional fund manager then invests that pool according to the fund's stated objective — growth, income, bonds, international stocks, or a specific index like the S&P 500.

Unlike stocks and ETFs, which trade on exchanges throughout the day, mutual funds only trade once per day at market close. The price you pay or receive is called the Net Asset Value (NAV) — the total value of the fund's holdings divided by the number of shares outstanding. If the fund holds $10 billion in securities and has 500 million shares outstanding, each share is worth $20.

You make money from a mutual fund in three ways: (1) dividends and interest from the underlying securities, which the fund typically distributes quarterly; (2) capital gains distributions when the manager sells securities for a profit; and (3) share price appreciation when the NAV increases.

Key difference from stocks:

You cannot place market orders, limit orders, or trade during the day. Every mutual fund trade settles at the 4:00 PM ET closing NAV price. This is the biggest functional difference between mutual funds and ETFs.

03Types of Mutual Funds

Stock (Equity) Funds

Invest primarily in stocks. Subcategories include large-cap, mid-cap, small-cap, growth, value, and sector funds. Highest long-term return potential, highest volatility.

Bond (Fixed Income) Funds

Invest in government and corporate bonds. Lower returns than stock funds but also lower volatility. Used for income and portfolio stability. Treasury, corporate, and municipal varieties.

Index Funds

Track a specific market index like the S&P 500 or total stock market. No active management — the fund simply holds whatever the index holds. Lowest fees (often 0.03-0.10%).

Target-Date Funds

Automatically adjust asset allocation from aggressive (stocks) to conservative (bonds) as you approach a target retirement year. The ultimate set-and-forget option for retirement accounts.

Money Market Funds

Invest in short-term, high-quality debt like Treasury bills. Extremely low risk, low returns. Used as a cash equivalent — not to be confused with money market accounts at banks.

Balanced (Hybrid) Funds

Hold a mix of stocks and bonds in a predetermined ratio like 60/40 or 70/30. One-fund diversification across asset classes. Moderate risk and return.

04Fees & Expense Ratios

The expense ratio is the annual fee every mutual fund charges, expressed as a percentage of your investment. It covers the fund manager's salary, administrative costs, marketing, and other operating expenses. This fee is deducted automatically — you never see a line item on a statement.

Fund Type	Typical Expense Ratio	Annual Cost on $100K
Fidelity Zero Index Fund	0.00%	$0
Vanguard/Schwab Index Fund	0.015% - 0.04%	$15 - $40
Low-Cost Active Fund	0.30% - 0.60%	$300 - $600
Average Actively Managed Fund	0.60% - 1.00%	$600 - $1,000
High-Fee Active Fund	1.00% - 2.00%	$1,000 - $2,000

The difference between 0.03% and 1.0% sounds small, but over 30 years on a $500,000 portfolio, the high-fee fund costs roughly $340,000 more in fees. That is not a typo. Fees are the single biggest drag on investment returns, and the one factor you can control. Always check the expense ratio before investing.

Use the Investment Fee Calculator to see exactly what fees cost you over time.

05Load vs No-Load Mutual Funds

A load is a sales commission charged when you buy (front-end load) or sell (back-end load) mutual fund shares. Loads typically range from 3% to 5.75% and go to the financial advisor who sold you the fund.

A no-load fund charges no sales commission at all. You buy directly from the fund company (Vanguard, Fidelity, Schwab) without a middleman taking a cut.

Glen's stance on loads:

Never buy a load fund. A 5% front-end load means $5,000 of every $100,000 you invest goes straight to the salesperson before a single dollar is invested. No-load index funds from Vanguard, Fidelity, and Schwab are superior in every measurable way. If an advisor recommends a load fund, they are prioritizing their commission over your returns.

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06How to Buy Mutual Funds

Open a brokerage or retirement account

Open an account at Fidelity, Schwab, or Vanguard. This can be a taxable brokerage account, a Roth IRA, a traditional IRA, or a 401(k) through your employer. All major brokers offer mutual funds with no transaction fees for their own funds.

Search for the fund by ticker symbol

Every mutual fund has a unique ticker symbol. VTSAX (Vanguard Total Stock Market), FXAIX (Fidelity 500 Index), SWTSX (Schwab Total Stock Market). Look up the fund, check the expense ratio, and confirm the minimum investment.

Place your order (dollar amount)

Unlike ETFs, you buy mutual funds in dollar amounts, not share quantities. You can invest $1,000 and the fund will give you the corresponding number of shares (including fractional shares) at the closing NAV price.

Set up automatic investments

Most brokers let you set up recurring monthly investments into mutual funds. This is the biggest advantage mutual funds have over ETFs — true automated dollar-cost averaging without needing fractional share support.

07Mutual Funds vs ETFs

Feature	Mutual Fund	ETF
Trading	Once daily at closing NAV	Anytime during market hours
Minimum Investment	$0 - $3,000 depending on fund	Price of 1 share (fractional at most brokers)
Expense Ratios	0.015% - 2.0%	0.03% - 0.75% (generally lower)
Tax Efficiency	Less efficient (capital gains distributions)	More efficient (in-kind redemptions)
Automatic Investing	Yes — exact dollar amounts on schedule	Yes at most brokers (fractional shares)
Fractional Shares	Always — you invest in dollar amounts	Available at most major brokers now
Order Types	Market order only (NAV)	Market, limit, stop-loss, etc.

For new investors, the choice increasingly favors ETFs. They are cheaper, more tax-efficient, and now offer fractional shares at most brokers. But if your 401(k) only offers mutual funds, or you love the simplicity of investing exact dollar amounts on a schedule, mutual funds work perfectly fine. The underlying investments are what matter — not the wrapper.

Deep dive: What Is an ETF? · VOO vs VTI

08Pros & Cons

Pros

+Instant diversification — one fund holds hundreds or thousands of securities
+Professional management — especially valuable in bond markets
+Dollar-amount investing — invest exactly $500, not "2.7 shares"
+Automatic investing — set up monthly contributions effortlessly
+Available in virtually every 401(k) and employer retirement plan
+Index mutual funds charge as little as 0.015% annually

Cons

-Trade only once per day — cannot react to intraday price movements
-Some funds have $1,000 - $3,000 minimums for initial investment
-Less tax-efficient than ETFs in taxable accounts
-Actively managed funds charge high fees (0.5% - 2.0%)
-Capital gains distributions can create tax liability even if you did not sell
-Load funds charge sales commissions up to 5.75%

09Best Mutual Funds for Beginners

FZROXFidelity ZERO Total Market Index Fund

Expense Ratio: 0.00%Minimum: $0

Literally zero expense ratio. Covers the entire U.S. stock market. Only available at Fidelity.

VTSAXVanguard Total Stock Market Index Fund

Expense Ratio: 0.04%Minimum: $3,000

The gold standard of index investing. Holds ~3,600 U.S. stocks. Warren Buffett recommended Vanguard index funds in his will.

FXAIXFidelity 500 Index Fund

Expense Ratio: 0.015%Minimum: $0

Tracks the S&P 500 with the lowest expense ratio of any S&P 500 mutual fund. No minimum investment.

SWTSXSchwab Total Stock Market Index Fund

Expense Ratio: 0.03%Minimum: $0

Total U.S. market exposure at rock-bottom cost. No minimum. Schwab's excellent customer service is a bonus.

VFIAXVanguard 500 Index Fund

Expense Ratio: 0.04%Minimum: $3,000

The original index fund (launched 1976). Tracks the S&P 500. Bogle's invention that changed investing forever.

Full comparison: Best Index Funds — Top 10 Compared

10Glen's Take

Mutual funds built the American middle class's retirement wealth. But the industry has evolved — and for most investors today, low-cost index ETFs are the better choice.

Here is what I tell people: If your 401(k) only offers mutual funds, invest in the lowest-cost index option available. If you are investing on your own in a brokerage account or IRA, use ETFs instead — they are cheaper, more tax-efficient, and more flexible.

The one case where mutual funds genuinely win: automatic investing of exact dollar amounts. If you want to invest exactly $500 on the 1st of every month with zero friction, mutual funds still handle this more smoothly than ETFs at some brokers. But this advantage is shrinking as more brokers add fractional ETF shares.

Regardless of which wrapper you choose — mutual fund or ETF — the math is the same. Keep fees below 0.10%. Invest consistently. Do not try to time the market. Let compound interest do the work. The wrapper matters far less than the behavior.

Frequently Asked Questions

What is a mutual fund in simple terms?

A mutual fund is a pool of money collected from many investors and managed by a professional fund manager. The manager buys a diversified portfolio of stocks, bonds, or other securities. When you buy shares of a mutual fund, you own a small slice of everything the fund holds. It is the simplest way to get diversification without picking individual stocks.

How do mutual fund fees work?

Every mutual fund charges an expense ratio — an annual percentage fee taken from the fund's assets. An expense ratio of 0.50% means you pay $50 per year for every $10,000 invested. Index mutual funds charge as little as 0.015% while actively managed funds can charge 1.0% or more. Over decades, this fee difference costs hundreds of thousands of dollars.

What is the difference between a mutual fund and an ETF?

Both hold baskets of securities, but ETFs trade on stock exchanges throughout the day like individual stocks, while mutual funds only trade once per day at the closing price (the NAV). ETFs are generally more tax-efficient and often cheaper. Mutual funds sometimes have lower minimums and allow automatic investments in fractional amounts. For most investors today, ETFs are the better choice.

Are mutual funds a good investment?

Low-cost index mutual funds are excellent investments for long-term wealth building. They provide instant diversification and professional management at minimal cost. However, actively managed mutual funds with high expense ratios (1% or more) have historically underperformed index funds about 90% of the time over 15-year periods. The key is keeping costs low.

How much money do I need to invest in a mutual fund?

Minimums vary by fund company. Vanguard Admiral Shares require $3,000. Fidelity and Schwab index funds have $0 minimums. Many 401(k) plans let you invest any amount. If the minimum is too high, consider the ETF version of the same fund — ETFs have no minimum beyond the price of one share (and most brokers now support fractional shares).

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