ETF Investing for Teens: The Case for Starting Boring and Building Wealth

The financial products that get the most attention—individual stocks, options, crypto—are almost never what produces lasting wealth for ordinary investors. What produces lasting wealth, documented across decades of data, is almost aggressively boring: broad market index funds with low expense ratios, held for a long time.

For teenagers beginning to invest, this is simultaneously the best news and the hardest pitch. ETFs aren’t exciting. You don’t get to talk about them at school. They don’t have a story. They just tend to work, at a rate that beats most alternatives over 20-year and 40-year periods.

This article explains what ETFs actually are, why the expense ratio number matters more than most people realize, and what the first ETF purchase looks like practically for a teenager who’s ready to start.

Key Takeaways

• ETFs (Exchange-Traded Funds) are baskets of securities—often tracking an entire market index—that trade on an exchange like a single stock.
• The expense ratio is the annual fee charged as a percentage of assets. A 0.03% expense ratio on a $10,000 investment costs $3/year. A 1.5% expense ratio costs $150/year. Over 40 years, that difference is enormous.
• S&P SPIVA (Standard & Poor’s Indices Versus Active) scorecards show that over 15-year periods, roughly 90% of actively managed U.S. equity funds underperform their benchmark index.
• Warren Buffett’s famous bet against a hedge fund—that a simple S&P 500 index fund would outperform a portfolio of hedge funds over 10 years—was won by the index fund decisively.
• The first ETF investment for a teenager works best inside a custodial brokerage account or custodial Roth IRA—not a bank account—because the growth needs time and tax-advantaged space to compound fully.

What an ETF Is (and How It Differs from Stocks and Mutual Funds)

An ETF (Exchange-Traded Fund) is a collection of securities—stocks, bonds, or both—that trades on a stock exchange under a single ticker symbol, just like a share of Apple or Tesla.

When you buy one share of a broad market ETF like VTI (Vanguard Total Stock Market ETF), you’re buying a tiny fractional ownership of approximately 3,600 U.S. companies simultaneously. Your one share includes pieces of Apple, Microsoft, Nvidia, Amazon, and thousands of smaller companies—proportional to their market value. When the U.S. stock market goes up, your ETF goes up. When it goes down, your ETF goes down.

ETFs vs. mutual funds: Both are baskets of securities. The key differences:

• Mutual funds are priced once per day after market close; ETFs trade throughout the day at market prices.
• Mutual funds often have minimum investments ($1,000–$3,000); most ETFs can be purchased for one share’s price, and many brokerages now offer fractional shares.
• ETFs are generally more tax-efficient than actively managed mutual funds.

ETFs vs. individual stocks: When you buy one stock, your returns depend entirely on that one company’s performance. One company can go bankrupt; an index containing 3,600 companies cannot. Diversification is built in.

The Expense Ratio: The Number That Matters Most

Every ETF and mutual fund charges an annual management fee expressed as a percentage of your total investment. This is the expense ratio. You never see this fee as a line item—it’s deducted from the fund’s returns daily. But over decades, it’s one of the most significant determinants of your final portfolio value.

Here’s the math:

Starting investment: $10,000 Annual return before fees: 7% Period: 40 years

Expense Ratio	Annual Fee on $10K	Portfolio at 40 Years	Lost to Fees
0.03% (Fidelity FZROX, SPDR SPY)	$3	~$143,000	~$3,000 lifetime
0.20% (mid-range index)	$20	~$131,000	~$15,000 lifetime
0.80% (actively managed fund)	$80	~$106,000	~$40,000 lifetime
1.50% (typical actively managed)	$150	~$79,000	~$67,000 lifetime

Assumes 7% annual gross return, compounded annually. For illustration only.

The difference between a 0.03% ETF and a 1.5% mutual fund over 40 years is more than $64,000 on a $10,000 investment. That’s nearly 45% of the cheaper fund’s final value—lost entirely to management fees.

For a teenager starting with small amounts and 50+ years ahead, the expense ratio is arguably the single most important number to understand.

Why Index Funds Beat Active Management Over the Long Run

The core argument for index ETFs over actively managed funds is not theoretical—it’s empirical.

S&P Global’s SPIVA (S&P Indices Versus Active) scorecards, which have been published annually since 2002, track the performance of actively managed funds against their benchmark indices. The 2023 SPIVA U.S. Scorecard found:

• Over the 15-year period ending December 2023, approximately 88% of actively managed U.S. large-cap equity funds underperformed the S&P 500.
• Over 20-year periods, the underperformance rate consistently exceeds 90%.

Why? Active funds must overcome two structural disadvantages: higher fees (typically 0.5%–1.5% annually versus 0.03% for index ETFs) and the fundamental difficulty of consistently predicting which stocks will outperform. Even professional fund managers with Bloomberg terminals, research teams, and years of experience fail to beat the market consistently over long periods.

This is why Warren Buffett’s famous “Bet” against a hedge fund manager proved so decisive. In 2008, Buffett wagered $1 million that a simple Vanguard S&P 500 index fund would outperform a portfolio of actively managed hedge funds over 10 years. By 2017, the index fund had returned 125.8%. The hedge fund portfolio had returned 36.3%. The charity of Buffett’s choosing received $1 million.

His will, he has noted publicly, directs that 90% of his wife’s inheritance go into a Vanguard S&P 500 index fund. The man who built one of the world’s greatest fortunes through active stock picking recommends passive index investing for everyone else.

How to Pick the First ETF

For a teenager’s first investment, simplicity is a virtue. The goal is to own the broad market at the lowest possible cost. Here are the most commonly recommended options:

Broad U.S. market ETFs:

• VTI (Vanguard Total Stock Market ETF) – 0.03% expense ratio, ~3,600 U.S. stocks
• FZROX (Fidelity Zero Total Market Index Fund) – 0.00% expense ratio (Fidelity-only, no transaction fees)
• SCHB (Schwab U.S. Broad Market ETF) – 0.03% expense ratio

S&P 500 ETFs (500 largest U.S. companies):

• VOO (Vanguard S&P 500 ETF) – 0.03% expense ratio
• SPY (SPDR S&P 500 ETF Trust) – 0.0945% expense ratio (most widely held, but slightly higher cost than VOO)

Global diversification (for a second or third ETF):

• VT (Vanguard Total World Stock ETF) – 0.07% expense ratio, covers U.S. and international markets

For most teenagers, VTI or VOO is a perfectly sensible starting point. One ETF, inside a Roth IRA or custodial brokerage, held for decades. That’s the strategy.

Where to Open the Account

ETFs live inside investment accounts—not bank accounts. For teenagers:

Custodial brokerage account: Opened by a parent in the teenager’s name. The parent controls it until the child reaches the state’s age of majority (18 or 21). No special income requirement.

Custodial Roth IRA: Requires the teenager to have earned income. Contributions are capped at earned income or $7,000/year (2026 limit), whichever is lower. Growth is tax-free. This is the stronger long-term choice if your teenager has earned income.

Both Fidelity and Schwab offer custodial accounts with no minimums and no annual fees. Fidelity’s FZROX has a zero expense ratio and no minimum investment, making it the most accessible entry point for small amounts.

What to Watch For Over 3 Months

Month 1: Open the account, make the first contribution, and invest it. Don’t wait for the “right moment”—time in the market matters more than timing the market. Even $100 in VTI is a real investment with real tracking. Log in once a month, not daily.

Month 2: Have your teenager look at what VTI actually holds. Fidelity and Vanguard both publish holdings lists. Looking up the 10 largest holdings in VTI (Apple, Microsoft, Nvidia, Amazon, etc.) connects the abstract “I own an ETF” to the concrete “I own tiny pieces of these actual companies.”

Month 3: Introduce the idea of automatic investing. Setting up a recurring monthly contribution—even $25 or $50—removes the decision-making friction and builds the habit of paying yourself first. Dollar-cost averaging (investing a fixed amount on a fixed schedule regardless of market conditions) is a strategy that reduces the psychological cost of market volatility for new investors.

Red flag: If your teenager is checking the account daily and feeling anxious about short-term price movements, introduce the concept that market fluctuations are normal and expected. An S&P 500 ETF drops 10% or more roughly every other year on average—and recovers. The goal of a long-term investor is to ignore short-term noise.

Frequently Asked Questions

Is there a minimum amount to start investing in ETFs?

At Fidelity or Schwab, you can start with as little as $1 using fractional shares. Vanguard’s custodial accounts also offer fractional shares for ETFs. The practical answer is: whatever your teenager can invest without needing the money back short-term. $50 or $100 is a meaningful real-world learning investment.

What’s the difference between a total market ETF and an S&P 500 ETF?

An S&P 500 ETF tracks the 500 largest publicly traded U.S. companies. A total market ETF tracks the entire U.S. market—approximately 3,600 companies, including those 500 plus thousands of smaller ones. Historical returns are very similar; total market funds provide slightly more diversification. Either is appropriate for a long-term investor.

Should a teenager pick individual stocks instead of ETFs?

For most teenagers, index ETFs outperform individual stock picking over 15–20 year periods—and do so with much lower volatility and no single-company risk. Individual stock picking can be educational as a small percentage of a portfolio ($50 in a company you’re interested in) but shouldn’t be the primary strategy when the goal is wealth building.

What happens to the ETF if Vanguard or Fidelity goes out of business?

ETF assets are held separately from the brokerage’s own assets—they are not on Vanguard’s or Fidelity’s balance sheet. If either firm failed, the underlying securities would still exist and would be transferred to another custodian. This is different from a bank failure (where deposits are liabilities on the bank’s balance sheet) and is one reason ETFs carry a different risk profile than cryptocurrency held at an exchange.

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About the author

Ricky Flores is the founder of HiWave Makers and an electrical engineer with 15+ years of experience building consumer technology at Apple, Samsung, and Texas Instruments. He writes about how kids learn to build, think, and create in a tech-saturated world. Read more at hiwavemakers.com.

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Sources

1. S&P Global. (2023). “SPIVA U.S. Scorecard: Year-End 2023.” S&P Global. https://www.spglobal.com/spdji/en/research-insights/spiva/
2. Vanguard. (2023). “The Case for Low-Cost Index Fund Investing.” Vanguard Research. https://investor.vanguard.com/investing/investment/index-funds
3. Fidelity Investments. (2024). “Fidelity ZERO Funds.” Fidelity. https://www.fidelity.com/mutual-funds/fidelity-funds/zero-expense-ratio-index-funds
4. Buffett, W. (2017). “Berkshire Hathaway Annual Letter to Shareholders.” Berkshire Hathaway. https://www.berkshirehathaway.com/letters/2017ltr.pdf
5. Morningstar. (2023). “Active vs. Passive Fund Performance Research.” Morningstar. https://www.morningstar.com/
6. U.S. Securities and Exchange Commission. (2023). “Investor Bulletin: Exchange-Traded Funds (ETFs).” SEC. https://www.sec.gov/investor/alerts/etfs.pdf