Buffett's multiple warnings convey the same message: Beware of an overvalued stock market.Warren Buffett will step down as Berkshire Hathaway's (BRK.A 1.34%) (BRK.B 1.76%) CEO at year-end. He isn't fully retiring, though. The investing icon will continue to serve as Berkshire's executive chairman. In his last few days at Berkshire's helm, Buffett is also leaving some subtle and not-so-subtle warnings for Wall Street. What are his warnings – and what should investors do as 2026 approaches? Buffett's subtle w ...