美股三大指数下跌，中概股龙头普跌，黄金、原油上涨丨美股开盘

Market Overview - On February 19, US stock indices opened lower, with the Dow Jones down 0.36%, Nasdaq down 0.51%, and S&P 500 down 0.28% [1] - Major technology stocks experienced a decline, with most large tech companies showing losses [1] Technology Sector - OpenAI is reportedly nearing the completion of the first phase of a new funding round, expected to exceed $100 billion, with a potential overall valuation surpassing $850 billion, up from an initial estimate of $830 billion [4] - The pre-funding valuation for OpenAI is expected to remain at $730 billion [4] - Key strategic investors in this funding round include Amazon, SoftBank, Nvidia, and Microsoft, with final investment decisions anticipated by the end of the month [4] - Nvidia's CEO Jensen Huang mentioned preparations for new chips for GTC 2026, emphasizing the challenges in technology development [4] Retail Sector - Walmart's stock rose nearly 2% after initially dropping over 3%, following the company's forecast for adjusted earnings per share of $2.75 to $2.85 for the fiscal year 2027, which is below market expectations [4] Chinese Stocks - The Nasdaq Golden Dragon China Index fell by 0.41%, with major Chinese stocks like Alibaba, Pinduoduo, and Tencent ADR all experiencing declines [6] - Specific declines include Alibaba down 0.63%, Baidu down 0.79%, and Tencent down 0.66% [7] Commodity Market - As of the latest update, spot gold increased by 0.17%, and spot silver rose by 0.77% [6] - WTI crude oil futures rose by 1.68% to $66.14 per barrel, while Brent crude oil futures increased by 1.54% to $71.43 per barrel [6]