The S&P 500 and broader US stock market are exhibiting unprecedented valuation levels, surpassing peaks seen during the 2000 Dot-Com Bubble. The S&P 500 Price-to-Book ratio reached a record 5.3 times, exceeding the Dot-Com peak and well above the long-term average of approximately 2.0. The Price-to-Sales ratio for the S&P 500 hit 3.4 times, also surpassing the 2000 bubble peak. The technology sector within the S&P 500 shows even more extreme valuations, with its Price-to-Sales ratio reaching 10 times, higher than the 7.8 times peak in 2000. Additionally, the S&P 100 index has 27% of its stocks trading at Price-to-Earnings ratios above 50, with 66 stocks above 30 and only one below 10. The overall US stock market capitalization relative to GDP has hit a record 211%, rising 45 percentage points in three months, well above the Dot-Com peak of around 144%. The NASDAQ market cap relative to US GDP reached 105%, nearly double since the 2022 bear market and about 40 percentage points above the 2000 peak, also setting a record relative to world GDP. Furthermore, the NASDAQ market cap relative to the US M2 money supply is at an all-time high of 145%, exceeding the Dot-Com Bubble peak. NVIDIA's weighting in the S&P 500 has surged to a record 8.2%, more than triple the entire energy sector's weight, which includes 25 stocks. At the start of 2024, NVIDIA's share was about 3%, comparable to the energy sector. These valuation metrics indicate elevated market risk and historic levels of concentration in a few large technology stocks.