Index funds have quietly made millions of ordinary investors wealthy. They also consistently beat 80% of actively managed funds over a 10-year period. This is not a secret Wall Street wants you to know.

What Is an Index Fund?

An index fund is a portfolio that tracks a market index — most commonly the S&P 500, which represents the 500 largest US companies by market cap. When you buy an S&P 500 index fund, you own a tiny slice of Apple, Microsoft, Amazon, Nvidia, and 496 other companies in a single purchase.

The core insight: Instead of trying to pick winning stocks (which even professionals rarely do consistently), you own the entire market. When the economy grows, you grow with it.
Advertisement
300×250 Display Ad

Why Index Funds Win

The data is unambiguous. According to S&P's SPIVA report, over 15 years:

  • 88% of large-cap active funds underperformed the S&P 500
  • 92% of mid-cap active funds underperformed their benchmarks
  • The average actively managed fund charges 1.0%+ in annual fees vs. 0.03% for Vanguard's index funds

That fee difference — 0.97% annually — sounds small. On a $100,000 portfolio over 30 years at 7% growth, it costs you $137,000 in foregone returns.

The Three Funds You Need

Most financial advisors charge thousands of dollars to build portfolios that are worse than this three-fund approach:

  1. US Total Market Fund (e.g., FSKAX, VTI) — Your core US holding
  2. International Index Fund (e.g., FZILX, VXUS) — Diversification outside the US
  3. Bond Index Fund (e.g., FXNAX, BND) — Stability, especially as you age
Best for Beginners

Fidelity

$0 commissions
  • ZERO expense ratio index funds (literally free)
  • No account minimums
  • Fractional shares — invest with any dollar amount
  • Best-in-class mobile app
Open Free Account →

VaultSignal may earn a commission when you open an account.

How to Allocate

A classic rule of thumb: subtract your age from 110. That's your stock percentage. At 30, you'd hold 80% stocks, 20% bonds. As you approach retirement, bonds provide stability when you can't afford a 40% market drop.

Advertisement
728×90 Leaderboard Ad

Start Today

The single biggest mistake investors make is waiting for the "right time." Studies consistently show that time in the market beats timing the market. If you invested $500/month in an S&P 500 index fund starting at 25, you'd have approximately $1.7 million at 65 — without ever picking a single stock.