US stock market valuations have reached unprecedented levels, surpassing peaks seen during the 2000 Dot-Com Bubble. The geometric average of four long-term valuation metrics for the S&P 500 has hit 163%, more than three standard deviations above the mean, compared to 126% at the Dot-Com peak. The S&P 500 trades at 22 times forward earnings expectations for the next 12 months, marking one of the highest valuations in 35 years. The NASDAQ market capitalization relative to US GDP has reached a record 127%, nearly doubling since the 2022 bear market low and exceeding the Dot-Com peak by approximately 50 percentage points. Similarly, the US stock market capitalization to GDP ratio stands at a record 211%, rising 45 percentage points in the last three months, well above the Dot-Com peak of about 144%. The S&P 500 Technology Sector Price-to-Sales ratio has climbed to 10 times, the highest ever recorded, surpassing the 7.8 times ratio during the Dot-Com Bubble. The Shiller P/E ratio on the S&P 500 reached 38.7 times, the highest since the Dot-Com Bubble burst and well above its long-term average of 17.6 times. Globally, the 12-month forward P/E ratio for the Information Technology sector in the MSCI World index hit 27 to 28 times, placing it in the top 10% of the most expensive readings in the past two decades. Growth stocks have also reached historically high forward P/E ratios near 26 to 27 times. NVIDIA's market capitalization now accounts for a record 3.6% of global GDP and 13.4% of US GDP, exceeding the market sizes of the UK, France, or Germany, and surpassing Cisco's 1.6% of world GDP at the Dot-Com peak. Investor sentiment surveys show that 91% of Fund Manager Survey participants believe US equities are overvalued, while 49% consider emerging markets undervalued. There is a notable divergence between retail and institutional investors, with retail investors purchasing $190 billion in US equity ETFs in 2025, while institutional investors have sold $40 billion over the same period.