US Equity Valuations Reach Historic Peaks Amid Market Euphoria

US equity markets have staged a rapid recovery, with the S&P 500 and Nasdaq Composite reaching new record highs by mid-April 2026. This surge follows a brief period of volatility in late March, during which the Dow Jones Industrial Average and Nasdaq entered correction territory, with the latter peaking 13% below its all-time high. Investor sentiment is currently buoyed by the prospect of a swift resolution to the conflict in Iran and the aggressive growth prospects for artificial intelligence infrastructure and applications. The Nasdaq recently recorded its longest winning streak of the century, logging 13 consecutive trading days of gains. Despite the rally, the Shiller Price-to-Earnings (CAPE) Ratio indicates severe overvaluation. The ratio has fluctuated between 39 and 41 over the last seven months, marking the second-highest valuation level since January 1871. This stands in stark contrast to the 155-year average of approximately 17.4. Historical data suggests these levels are a warning sign. In the previous five instances where the CAPE Ratio exceeded 30 during a continuous bull market, the Dow, S&P 500, or Nasdaq subsequently experienced declines of at least 20%. This valuation stress is mirrored by the strategic moves of Berkshire Hathaway. For 13 consecutive quarters leading up to the end of 2025, the firm acted as a net seller of equities, offloading approximately $187 billion more in stocks than it purchased, signaling a lack of attractive value propositions in the current market.