What is an index fund? An index fund is an investment that automatically owns a slice of every company in a market index (like the S&P 500). Rather than picking individual stocks, you own the entire market in one purchase. It is the most recommended starting point for new investors because of its simplicity, low cost, and historically strong long-term performance.
WHAT IS THE S&P 500?
The S&P 500 is a list of the 500 largest US-listed companies by market value. It includes Apple, Microsoft, NVIDIA, Amazon, and 496 other companies. When people say "the market went up 1% today," they usually mean the S&P 500 went up 1%.
An S&P 500 index fund automatically holds all 500 companies in proportion to their size. When NVDA grows, your slice of NVDA grows. When a company shrinks out of the top 500, it's automatically replaced.
WHY WARREN BUFFETT RECOMMENDS INDEX FUNDS
"A low-cost index fund is the most sensible equity investment for the great majority of investors." — Warren Buffett, Berkshire Hathaway Annual Letter
The reason: research consistently shows that approximately 80-90% of actively managed funds (where experts pick stocks) underperform a simple S&P 500 index fund over 20-year periods. The main culprit is fees — an active fund charging 1% annually has to beat the market by more than 1% every year just to match a free index fund.
HOW MUCH WOULD YOU HAVE MADE?
£10,000 invested in an S&P 500 index fund in January 2004: approximately £82,000 by March 2026 (with dividends reinvested). No stock picking required. No market timing. Just holding.
HOW TO INVEST IN AN INDEX FUND
Open a brokerage account (Fidelity, Vanguard, Charles Schwab in the US; Hargreaves Lansdown, Trading 212 in the UK)
Search for VOO, SPY, or VTI (US) / VWRP or CSPX (UK)
Buy any dollar amount — fractional shares are available on most platforms
Set up a monthly automatic investment if possible
FREQUENTLY ASKED QUESTIONS
Which index fund is best for beginners?
For US investors, VOO (Vanguard S&P 500 ETF, 0.03% annual fee) or FXAIX (Fidelity S&P 500, 0.015%) are the most commonly recommended. For UK investors, VWRP (Vanguard Global) or CSPX (iShares S&P 500) are popular. The differences between the major providers are minimal — low cost and broad market coverage are the key criteria.
Is now a good time to buy an index fund?
Research consistently shows that time in the market beats timing the market. Studies comparing investors who invested lump sums at market peaks versus investors who waited for better prices found the lump-sum investors outperformed in the majority of 10+ year periods. For long-term investors, beginning immediately with monthly contributions is generally superior to waiting for a 'better time'.
What happens to an index fund if the stock market crashes?
An S&P 500 index fund falls with the market during crashes. The S&P 500 fell approximately 50% during the 2008 financial crisis, 34% during COVID (March 2020), and 19% during 2022. In each case, it fully recovered and went on to new highs. Long-term investors who held through these crashes recovered and profited. Investors who sold at the bottom locked in permanent losses.
Educational purposes only. MarketMVP OVR scores, tiers, and athlete comparisons are proprietary educational tools — not financial advice, investment ratings, or recommendations to buy or sell any security. Always conduct your own research. Full disclaimer