Warren Buffett’s stock market warning: Could record highs signal a crash? Here’s what history reveals about what comes next

Warren Buffett’s warning: Is a US stock market crash coming? The US stock market has had a remarkable year. The S&P 500, Nasdaq Composite and Dow Jones Industrial Average have all reached record levels at different points in 2026. But high prices do not remove risk. Investors are paying more for some shares as concerns grow about bond yields and the cost of building AI infrastructure. On October 19, the S&P 500 and Nasdaq recovered while the Dow slipped.

Warren Buffett’s warning is relevant, but it is not a prediction of a crash on a particular date. He is concerned that some investors are treating the market as a place for quick bets rather than long-term ownership.

Warren Buffett’s warning: Is a US stock market crash looming?

In a CNBC interview in May, Buffett compared the stock market to “a church with a casino attached”. He was describing the difference between investing in a business and making short-term bets in the hope of quick gains.


He was especially critical of one-day options trading, which can expose investors to sharp losses in a short period.

His point was not that every stock is a bad investment. He warned that excitement could push the prices of many assets to levels that look “very silly”. A company may have promising technology, but that does not mean its shares are worth any price. When buyers focus on prices rising instead of profits justifying valuations, disappointment can turn into selling.

Berkshire Hathaway’s cash reserve has added to the discussion. Its latest financial report showed that its insurance and other businesses held about $359.2 billion in cash, cash equivalents and US Treasury bills on June 30, 2026.

That is a huge reserve, but not proof that Buffett knows a crash is near.

Berkshire needs liquidity to run its businesses, and Buffett has long preferred to wait rather than buy at an unattractive price. Cash also gives the company room to act when better opportunities appear.

What the CAPE ratio says about today’s valuations

One measure investors watch is the S&P 500 Shiller CAPE ratio. It compares share prices with the average inflation-adjusted earnings of the previous 10 years, smoothing out unusually strong or weak years to offer a longer-term view of valuations.

Recent readings have stayed around 40, a level seen only rarely in the index’s history. The published monthly figure was 40.58 for September 2026, while the October estimate was around 40.7. The ratio reached about 44.2 during the dot-com boom in December 1999. The bear market that followed began in 2000, after many technology shares had risen to prices their businesses could not support.

Still, a high CAPE ratio does not mean a crash must happen soon. Valuations can remain elevated for years if profits grow or investors continue to expect strong returns. The ratio cannot predict the timing or depth of a decline.

It does suggest that expectations are demanding. When shares are expensive relative to long-term earnings, the market has less room for bad news. Disappointing profits, high interest rates or heavy AI spending that fails to deliver expected growth could put pressure on prices.

Berkshire’s latest investments reveal where the company sees value

Berkshire Hathaway has continued to invest despite holding a huge cash reserve.

On October 14, 2026, the company invested an extra $330 million in Bending Spoons, an Italian tech firm owning platforms like Vimeo and AOL. This brings Berkshire’s total stake in the company to $930 million (a 4% share), following its initial $600 million input during Bending Spoons' July IPO.

Under CEO Greg Abel, the firm is showing that it won't sit entirely on the sidelines when a solid digital deal comes along.

At the same time, the core stock portfolio remains rooted in blue-chip industry giants.

As per its June 30 regulatory report, Berkshire’s portfolio stood at roughly $299.3 billion, heavily backed by top names like Apple ($51 billion), American Express ($50.4 billion), Alphabet ($33 billion), and Coca-Cola ($23 billion).

How investors can prepare

Nobody can reliably identify the exact market peak in advance. Those who move all their money out may avoid a fall, but they can also miss further gains and struggle to decide when to return.

A more real approach is to examine a company’s earnings, debt, cash generation and competitive position.

Even a popular company can be a poor investment if its share price already assumes years of exceptional growth.

A market decline does not make every business weak, either.

Companies with sound finances and steady demand may be better placed to withstand difficult periods.

Nassim Nicholas Taleb’s Black Swan Theory offers a lesson. Taleb, a Lebanese-born American scholar and former Wall Street trader, wrote about rare, unpredictable events that can cause serious damage.

His idea of “antifragility” takes this further. Instead of merely surviving uncertainty, an antifragile approach aims to benefit from it.

In practice, this may mean keeping some cash, limit the debt, diversify the investments and avoid bets.

Some strategies combine conservative assets with a smaller allocation to high-risk investments, but they do not guarantee profits and may not suit everyone.