According to data from Apollo Global Management, stock valuations are approaching their highest levels in 145 years. The firm's Chief Economist Torsten Slok wrote, "The Cyclically Adjusted Price-to-Earnings ratio (CAPE), also known as the Shiller P/E, is a measure of stock market valuation. It is calculated by dividing the current share price by the average inflation-adjusted earnings over the past 10 years, thereby smoothing out the fluctuations of the business cycle to assess long-term overvaluation or undervaluation and to forecast future returns." Slok further noted that "compared to the traditional P/E ratio which uses only one year of earnings, it provides a more accurate measure of sustainable profitability. The latest reading indicates that stock valuations are near their highest levels since 1880." Apollo's data shows that the current reading of approximately 39 is more than double the historical average. This implies that the expected annualized returns over the next decade could be very low, or even negative. Similar to the 2000 dot-com bubble, current valuations are highly concentrated in a handful of AI giants (such as NVIDIA, Microsoft, etc.). If the earnings growth delivered by AI fails to match their extremely high P/E ratios, the market will face significant downward pressure for a correction.