Warren Buffett issued a 10-word warning to investors, saying 'It's tough to find values when everybody is preferring gambling.' He pointed to record margin debt of $1.5 trillion, up 49% year over year, and a 46.2% surge in zero-day-to-expiration options volume in the first half of 2026 as signs of speculative behavior. Buffett's preferred valuation gauge, the ratio of total U.S. equity market cap to GDP, exceeded 335% in the first quarter of 2026, while the cyclically adjusted price-to-earnings ratio hit 40.4, a level seen only during the dot-com bubble. History suggests such stretched valuations could precede a market pullback, and highly leveraged positions may amplify any decline.