Index funds are the foundation of most sound long-term investment portfolios. They track a market index — like the S&P 500 or total stock market — and offer broad diversification at extremely low cost. For beginners, they are often the best place to start.
What Is an Index Fund?
An index fund is a type of mutual fund or exchange-traded fund (ETF) that passively tracks a market index rather than trying to beat it. Because there is no active management, costs are low. Over long time horizons, the majority of actively managed funds underperform their benchmark index after fees.
Best Index Funds for Beginners in 2026
1. Vanguard S&P 500 ETF (VOO)
VOO tracks the S&P 500, giving you ownership in 500 of the largest U.S. companies. With an expense ratio of 0.03%, it is one of the cheapest and most widely held funds in the world. It is the most common starting point for new investors.
- Expense ratio: 0.03%
- Index tracked: S&P 500
- Minimum investment: Price of one share (no minimum at most brokers)
2. Fidelity ZERO Total Market Index Fund (FZROX)
FZROX charges zero expense ratio — no annual fees at all. It covers the entire U.S. stock market, giving broader exposure than an S&P 500 fund. It is only available directly through Fidelity, but if you use Fidelity as your broker, it is hard to beat.
- Expense ratio: 0.00%
- Index tracked: Fidelity U.S. Total Investable Market Index
- Minimum investment: $1 (fractional shares available)
3. Schwab U.S. Broad Market ETF (SCHB)
SCHB tracks the Dow Jones U.S. Broad Stock Market Index, covering roughly 2,500 stocks. At 0.03% expense ratio, it matches VOO on cost while providing broader market exposure. A strong choice at Schwab or any broker.
- Expense ratio: 0.03%
- Index tracked: Dow Jones U.S. Broad Stock Market Index
- Minimum investment: Price of one share
4. iShares Core S&P Total U.S. Stock Market ETF (ITOT)
ITOT covers more than 3,500 U.S. stocks at an expense ratio of 0.03%. It is available at any brokerage and is a reliable total market fund for investors who want broad U.S. exposure without platform restrictions.
- Expense ratio: 0.03%
- Index tracked: S&P Total Market Index
- Available at: Any major brokerage
5. Vanguard Total World Stock ETF (VT)
VT holds stocks from every country in one fund — U.S. and international developed and emerging markets. For beginners who want a single fund that covers the entire global stock market, VT is the cleanest solution at 0.07% expense ratio.
- Expense ratio: 0.07%
- Holdings: ~9,000 stocks across 50+ countries
- Best for: Investors who want global diversification in one fund
S&P 500 vs. Total Market: Which Should You Choose?
Both are excellent choices. The S&P 500 covers large-cap U.S. companies. A total market fund adds mid-cap and small-cap stocks. The historical return difference is minimal. Most beginner investors do fine with either — picking one and investing consistently matters more than which fund you choose.
How to Invest in Index Funds
- Open a brokerage account at Fidelity, Schwab, or Vanguard (or a Roth IRA for tax advantages)
- Fund the account by linking your bank
- Search for the ticker (e.g., VOO, FZROX)
- Buy shares — most platforms now offer fractional shares so you can start with any amount
- Set up automatic contributions to invest consistently
Common Mistakes Beginners Make
- Buying too many overlapping funds that essentially hold the same stocks
- Checking the account too frequently and panic-selling during dips
- Waiting for the “right time” to invest rather than starting now
- Using a taxable account when a Roth IRA would provide better tax benefits
Bottom Line
For most beginners, a single low-cost index fund — VOO, FZROX, SCHB, or ITOT — is all you need to start building wealth. Open an account, invest what you can afford, set up automatic contributions, and let compounding do the work over time.
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