Core Viewpoint - Despite negative signs in the employment and real estate markets, major U.S. stock indices continue to rise, driven by unsustainable fiscal deficits and explosive growth in artificial intelligence spending. Analysts warn of a potential crisis reminiscent of the internet bubble [1]. Group 1: Valuation Concerns - Valuations have reached "crazy" levels, with the expected price-to-sales ratio of the S&P 500 Information Technology sector hitting 8.8 times, significantly higher than the levels seen at the end of the internet boom and the highest ever recorded [2]. - The Shiller price-to-earnings ratio is nearing 40, a level historically seen only twice, and is slightly below the peak reached in 1999. A CAPE above 25 indicates a period of "irrational exuberance" [5][6]. - The stock market capitalization to GDP ratio, known as the "Buffett Indicator," has reached a record high, indicating an overbought market [7]. Group 2: Market Dynamics - The return of "vendor financing" is noted, where companies like Cisco provided financing to customers purchasing their equipment, reminiscent of past market behaviors [9]. - Nvidia announced a potential investment of up to $100 billion in OpenAI to support the construction of data centers powered by Nvidia chips. Analysts are divided on this move, with some viewing it as a sign of robust AI infrastructure growth, while others see it as aiding a cash-strapped client [11][12]. - Market performance is increasingly polarized, with the top ten stocks accounting for about 40% of the total market value, similar to the late 1990s. Nvidia's market cap exceeds $4.3 trillion, surpassing the annual GDP of the UK and France, while Microsoft and Apple are also close to this valuation [13]. Group 3: Investor Sentiment - Factors such as FOMO (fear of missing out), momentum, algorithmic trading, and passive index investing may keep stock prices elevated despite high valuations. However, over time, such high valuations are difficult to sustain, suggesting that the current situation may not differ from past market behaviors [14].