Warren Buffett Has Recommended This 1 Investment for Decades. History Says It Could Turn $100 per Month Into $225,000.

Warren Buffett, the world's wealthiest person, has long advised people to invest in the S&P 500 (SNPINDEX: ^GSPC) for long-term growth. While he personally manages a small number of companies, he suggests a simpler approach for most investors: simply buying the index fund representing the 500 largest U.S. companies. In 2013, Buffett included instructions in his annual letter to Berkshire Hathaway shareholders to invest 90% of their money in a low-cost S&P 500 index fund.

He recommends Vanguard's version for its low expense ratio of just 0.03%. Over a 30-year period, a $100 monthly investment in this fund could grow to about $225,000, even after accounting for the initial $36,000 contributed. This strategy is favored because it avoids the risks of trying to time the market and requires minimal effort, as the fund tracks the performance of the U.S. economy's largest businesses. Buffett's endorsement adds credibility to this straightforward investment approach.