Most people who delay investing do not lack money to invest. They lack a clear starting point. Index funds eliminate most of the reasons that traditionally made investing feel complicated or risky for ordinary people. They require no stock-picking skill, carry very low costs, and have consistently outperformed the majority of actively managed funds over long periods. This guide walks through exactly how to begin, from opening an account to making your first contribution.
What an Index Fund Actually Is
An index fund is a pool of money that automatically buys every stock (or bond) in a specific market index, like the S&P 500 or the total U.S. stock market. Instead of a fund manager choosing which companies to buy, the fund simply mirrors the index. When the index goes up, the fund goes up by roughly the same amount. When it goes down, the fund follows.
The key advantage is cost. Active fund managers charge fees to pay for research, trading, and their own compensation. Index funds have no such overhead. The best index funds charge annual expense ratios below 0.05 percent, meaning you pay less than $5 per year on a $10,000 investment. Those savings compound over decades into meaningful additional returns.
Step 1: Decide Where to Open an Account
Before choosing funds, choose your account type. Your goal determines the right wrapper:
- Employer 401(k) or 403(b): Start here if your employer offers a match. The match is free money with an immediate 50–100 percent return on those dollars.
- Roth IRA: Contributions are after-tax, but growth and qualified withdrawals are tax-free. Ideal for people who expect to be in a higher tax bracket in retirement.
- Traditional IRA: Contributions may be tax-deductible now, and you pay taxes when you withdraw in retirement.
- Taxable brokerage account: No contribution limits, no early-withdrawal penalties, and no tax advantages. Use this after you have maxed out tax-advantaged accounts.
For most first-time investors, the sequence is: 401(k) up to the employer match, then Roth IRA up to the annual limit, then back to the 401(k) for any remaining capacity.
Step 2: Choose a Brokerage
The major brokerages (Fidelity, Vanguard, Schwab) all offer commission-free trading on index funds and ETFs and have no minimum account balances on most accounts. Your 401(k) is administered through whatever your employer uses. For an IRA or taxable account, any of these three is a reasonable default. All offer their own branded low-cost index funds with expense ratios at or near zero.
Step 3: Pick One or Two Funds to Start
Complexity is the enemy of getting started. A single total-market index fund covers thousands of U.S. stocks and is a complete investment on its own. If you want international diversification, add a total international stock market index fund. That two-fund portfolio covers virtually every publicly traded company in the world.
Common starting choices:
- Fidelity ZERO Total Market Index Fund (FZROX) — 0% expense ratio
- Vanguard Total Stock Market Index Fund ETF (VTI) — 0.03% expense ratio
- Schwab Total Stock Market Index (SWTSX) — 0.03% expense ratio
Do not agonize over which one to pick. At this cost level, the difference between them over 30 years is negligible. The fund you actually invest in today beats the theoretically optimal fund you research for another six months.
Step 4: Set a Contribution Amount and Automate It
Decide on a fixed monthly amount and set up an automatic transfer on payday. The amount matters far less than the consistency. $100 a month started at age 25 produces significantly more wealth than $300 a month started at age 35, even though the second scenario contributes far more total dollars. You can also read about the pay-yourself-first strategy to understand how to structure this habit.
Step 5: Do Not Watch It Daily
This is the step most people skip. The biggest behavioral risk in index fund investing is selling during a market decline and buying back in after recovery — the exact opposite of buying low and selling high. Market drops of 10, 20, or even 40 percent are normal over a multi-decade investing horizon. They are also temporary. Investors who held through every major downturn since 1950 recovered and then went significantly higher.
Set a quarterly reminder to check your contribution amount and rebalance if needed. Ignore it the rest of the time.
Common Questions
Is it too late to start? No. A dollar invested in a diversified index fund at 40 has 25 years to compound before a standard retirement age. Starting imperfectly now is better than waiting for the ideal conditions that never arrive.
What if the market crashes right after I invest? You invest over time through automatic contributions, so a crash shortly after you start means your next contributions buy at lower prices. This is dollar-cost averaging working in your favor.
Should I try to pick individual stocks too? Only with money you can afford to lose entirely, and only after your index fund contributions are automated. Individual stock picking underperforms index funds for the majority of retail investors over periods longer than five years.
The core insight behind index fund investing is that you do not need to be smarter than the market. You just need to own the market at low cost, contribute consistently, and wait. Those three conditions require no special knowledge and are available to anyone with a brokerage account and a small amount of money to start.