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.

Wall Street pointed slightly lower in early trading Friday but remains on track to close the week with solid gains with major corporations turning in largely healthy earnings reports. Futures for the S&P 500 ticked down 0.

Shares were mixed in thin Asian trading on Monday after U.S. stocks edged back from their all-time high. Oil prices fell and U.S. futures sank, while Chinese shares shed some of their early gains after a survey of manufacturers showed export orders dropping to a five-month low.