Warren Buffett's historic $127 billion warning to Wall Street happens to align with another stock market alarm. Specifically, the S&P 500 currently trades at a historically expensive valuation. The index achieved a cyclically adjusted price-to-earnings ratio (CAPE) of 37.9 in December 2024, which is a substantial premium to 20-year average of 27.

Investors often turn to Warren Buffett for advice for one good reason: He's proven his ability to navigate any investing waters -- from moments of euphoria to the doldrums -- and win over time. Buffett doesn't rush to buy the hottest stocks as markets soar and doesn't panic-sell during difficult periods.

Fact checked by Stella Osoba Warren Buffett has increasingly argued in recent years that it's not just the ubiquitous sports betting apps that have made your phone a pocket casino. In his 2024 annual letter to shareholders,

Warren Buffett has delivered market-beating performance over the long haul. Investors keep a close eye on the billionaire’s moves, hoping to follow some of his successes. Buffett’s latest move tells us something important and could impact whether we win or lose over the long term.