Apollo Global Management's Chief Economist Torsten Sløk has warned that the current artificial intelligence (AI) stock bubble surpasses the dot-com bubble of the late 1990s. The top 10 companies in the S&P 500, heavily influenced by AI-related firms such as Nvidia and Microsoft, are trading at approximately 28 times forward price-to-earnings (P/E) ratios, compared to about 25 times during the 2000 tech bubble peak. These top 10 companies now constitute nearly 40% of the S&P 500, the highest concentration ever recorded, while tech stocks make up 34% of the index, exceeding the 33% peak in 2000. Nvidia and Microsoft alone account for around 15% of the S&P 500's market capitalization, a level of dominance that eclipses the combined weight of consumer staples, energy, healthcare, and utilities sectors. Apollo's analysis suggests that this overvaluation and market concentration could lead to a correction more severe than the dot-com crash. Bank of America strategists, led by Michael Hartnett, have also expressed concerns about rising bubble risks in stock markets, attributing them to looser monetary policy and easing financial regulation. The warnings highlight growing apprehension over the sustainability of AI-driven market growth and the potential for a sharp downturn.