Billionaire Warren Buffett’s Warning Before the Dot-Com Crash Offers a Lesson for Today’s Investors

How can investors prepare for a possible stock market crash? Warren Buffett offered some advice more than 25 years ago that could be especially useful today.

As First for Money previously reported, Buffett, 96, stepped down as chairman of Berkshire Hathaway in September after more than five decades in the role. In his final shareholder meeting as CEO in 2025, he warned that excessive government spending and borrowing could weaken the U.S. dollar, calling the country’s long-term fiscal deficit “unsustainable,” according to Yahoo Finance.

The Motley Fool reported on Wednesday, October 21, that the S&P 500 had fallen nearly 2 percent over the previous week, while the Nasdaq Composite dropped more than 4 percent. With concerns growing about a deeper downturn, Buffett’s longtime strategy of investing in strong, established businesses could help investors weather the uncertainty.

Much of the recent market weakness has come from the technology sector, per the report. Rising bond yields have made borrowing more expensive for companies spending heavily on artificial intelligence data centers and infrastructure. According to the article, if those companies reduce their investments, the effects could spread across the stock market.

Per the report, in a 1999 essay for Fortune, written during the dot-com boom, Buffett cautioned investors after the S&P 500 had climbed nearly 200 percent over four years.

“The key to investing is not assessing how much an industry is going to affect society, or how much it will grow,” Buffett wrote, according to the Motley Fool, “but rather determining the competitive advantage of any given company and, above all, the durability of that advantage.”

Buffett’s concerns turned out to be justified. When the dot-com bubble burst in 2000, stocks entered a bear market that lasted more than two years. Hundreds of technology stocks plunged, per the report, which noted that the same lesson could apply to today’s AI boom. Although artificial intelligence has enormous potential, not every company investing in the technology will necessarily succeed.

Buffett’s focus is on companies with a lasting competitive advantage. The Motley Fool argued that investors should load up on quality stocks with strong fundamentals.

“The products or services that have wide, sustainable moats around them are the ones that deliver rewards to investors,” Buffett said, the Motley Fool reported.

And while market crashes can be painful, history shows that stocks can recover. Since the dot-com bear market began in March 2000, the S&P 500 has gained more than 715 percent, according to the outlet.