AI恐慌扩散，科技股再度拖垮美股，地产股连日重挫，苹果一日蒸发2000亿

Group 1 - The core viewpoint of the articles highlights a significant market downturn driven by fears surrounding the disruptive impact of artificial intelligence (AI) on traditional industries, leading to panic selling among investors [1][4][12] - Major U.S. stock indices fell over 1%, with the Nasdaq dropping approximately 2%, marking a three-day decline, while the Dow Jones Industrial Average closed below the 50,000 mark for the first time in a week [1][2] - The technology sector was identified as the primary culprit for the market decline, with Cisco's stock plummeting 12% due to disappointing gross margin guidance, and the "big seven" tech companies all experiencing losses [2][8] Group 2 - Concerns about the return on AI investments have intensified, with major tech firms like Amazon, Google, Meta, and Microsoft expected to spend around $650 billion on AI this year, raising doubts about whether such capital expenditures will yield tangible returns [4][6] - The narrative in the market has shifted from identifying beneficiaries of AI to recognizing potential victims, with sectors such as software, insurance brokerage, asset management, and commercial real estate facing significant pressure [6][11] - The commercial real estate sector has been particularly hard hit, with companies like CBRE and Jones Lang LaSalle seeing stock declines exceeding 25% over two days, as fears grow that AI could automate key functions and reduce demand for human brokers [5][12] Group 3 - The market sentiment has transitioned from "AI euphoria" to "AI phobia," with investors reassessing whether AI capital expenditures are overheated and if the commercialization of AI is lagging behind expectations [6][10] - Analysts have noted that the recent sell-off appears disproportionate to the actual risks, suggesting that the market may be overreacting to AI-related concerns [12] - Despite the overall downturn, some segments within the semiconductor industry, such as storage chip stocks, have managed to maintain gains, indicating a divergence within the tech sector [8][10]