Warren Buffett has long recommended the Vanguard S&P 500 ETF (VOO) as the ideal investment vehicle for long-term investors seeking to build wealth without active trading or complex strategies. In a 2013 letter to Berkshire Hathaway shareholders, Buffett outlined his own advice for long-term wealth creation: “Put 10% of the cash in short-term government bonds and 90% in a very low-cost S&P 500 index fund. (I suggest Vanguard’s.)”
The Vanguard S&P 500 ETF charges just 0.03% annually in expenses, making it one of the lowest-cost index funds available to retail investors. As of June 30, 2026, VOO held $979 billion in assets, part of a broader $1.7 trillion in total Vanguard S&P 500 Index fund assets across all share classes. The fund recently surpassed $1 trillion in total assets, a milestone that reflects its dominance among passive index investors.
Why Index Funds Outperform Active Management
Buffett’s recommendation rests on a simple but powerful principle: most professional money managers fail to consistently beat the market after fees. In fact, approximately 90% of actively managed funds underperform the S&P 500 index over extended periods, according to research cited across financial advisory sources.
To demonstrate this conviction, Buffett made a famous $1 million bet in 2007 with hedge fund managers, wagering that a low-cost S&P 500 index fund would outperform a hand-picked portfolio of five hedge funds over a 10-year period. The results were decisive: by the end of 2017, the S&P 500 index fund had returned approximately 85%, while the hedge fund portfolio significantly lagged behind. Buffett donated the $1 million winnings to a charity of his choice.
The S&P 500 itself provides natural diversification across 500 large-capitalization U.S. companies spanning multiple sectors. As of mid-2026, the index’s sector allocation included technology (33%), financials (13%), and communication services (10%), reflecting the economy’s evolving composition. This broad exposure eliminates the need for individual stock picking while capturing the long-term growth of the American economy.
Simplicity as the Core Strategy
Buffett emphasizes that his 90/10 framework—90% in a low-cost S&P 500 index fund and 10% in short-term government bonds—removes emotion from investing and eliminates the need for market timing. Investors who consistently buy the index fund regardless of market conditions benefit from dollar-cost averaging, reducing the impact of short-term volatility.
The fund’s minimal turnover (just 2% annually) and rock-bottom fees ensure that investor returns are not eroded by excessive trading costs. For long-term investors, this simplicity has proven superior to complex strategies managed by professionals charging higher fees. VOO’s 15.2% annualized return over recent years demonstrates the power of this straightforward approach, even during periods of market uncertainty.
Sources
- The Motley Fool — Buffett’s 2013 shareholder letter recommending 90% S&P 500 index fund allocation; VOO asset figures and performance data as of June 2026
- Vanguard — VOO expense ratio (0.03%), total assets ($979 billion as of June 30, 2026), sector allocation, and fund performance metrics
- Investopedia — Details on Buffett’s $1 million hedge fund bet (2007–2017) and index fund outperformance statistics
- Yahoo Finance — Recent coverage of Buffett’s long-standing recommendation for VOO and the rationale behind index investing for retail investors
