The S&P 500 forward Price to Sales ratio reached an all-time high of 2.9x in October, surpassing previous records. This significant increase in valuations marks the highest level since the end of the bear market two years ago, when the ratio was approximately 2.0x. The current market is considered one of the most expensive in over a century, even more so than the pre-1929 crash and nearing the levels seen during the Dot Com bubble. Investor allocation to stocks has also surged to 61%, the highest in at least 40 years, reflecting a bullish sentiment comparable to the Dot Com bubble era. Additionally, the stock market concentration risk has reached its highest level in more than 90 years, raising concerns about potential market instability.