Why are S&P 500 index funds popular?
An index fund is designed to mirror the performance of a stock index. An S&P 500 index fund doesn't try to outperform the index. Instead, it uses the index as its benchmark and aims to replicate its performance as closely as possible.
While S&P 500 funds are the most popular type of fund, index funds can be based on practically any financial market, investing strategy, or stock market sector. Index funds are popular with investors for a number of reasons. They offer easy portfolio diversification, with some funds providing broad exposure to hundreds or even thousands of stocks and bonds.
You don't risk losing all your money if one company collapses, as you could with individual investments. However, you also don't have as much upside potential for the astronomical returns that can result from picking a single huge winner.
Index funds are passively managed, meaning you're not paying someone to actively pick investments. Passively managed funds have lower expense ratios due to having lower investment management fees than actively managed funds.
Your money will track the market's performance
Historically, the S&P 500's annual returns have been in the range of 9% to 10%. In some years, the index will lose value. For example, during the Great Recession, the S&P 500 lost about half its value. Meanwhile, the index experienced a bear market starting in early 2022 and had declined by roughly 20% from its peak by the fall.
However, the index has largely rallied since then, posting the following gains:
- 2023: 24%
- 2024: 23%
- 2025: 16%
- 2026: 9% (through June 30, 2026)
Note that these positive returns have occurred in spite of several major sell-offs due to concerns about inflation, tariffs, AI overhype, and rising oil prices due to war in Iran.
The S&P 500 index has a solid history of such rebounds. Over the long term, the index has always recovered. A 20-year investment has never resulted in a loss in the S&P 500's history.
You will keep more of your investment profits
S&P 500 index funds are low-cost investments. While active managers are likely to match or even beat the market's performance over time, their fees eat away at your returns. Because they're passive investments with low fees, that mirror the index's long-term performance.
