美股三大指数涨跌不一，热门中概股普涨

Group 1 - U.S. stock indices showed mixed performance on August 18, with the Dow Jones up 0.05%, S&P 500 up 0.02%, and Nasdaq down 0.02% [1] - Novo Nordisk's stock rose over 5% after launching a cash-pay version of its weight loss drug Ozempic at $499 per month, half the list price [1] - Chinese stocks saw significant gains, with Xunlei up over 21%, iQIYI up over 16%, and Douyu up over 10% [1] Group 2 - Wall Street is focused on the upcoming Jackson Hole meeting, where Federal Reserve Chairman Jerome Powell will discuss economic and interest rate outlooks, potentially influencing rate cut bets [2] - The Nifty 50 index in India experienced its best single-day performance in three months, rising 1.6% to 25,022 points, driven by positive tax reform rumors [3] Group 3 - The Nikkei 225 index in Japan reached a historical high, rising 0.95% to 43,789.19 points, supported by a weaker yen boosting auto exports [4] - XPeng Motors secured a strategic cooperation agreement with CITIC Bank, receiving a credit line of 10 billion yuan to support its operations and development [5] Group 4 - Samsung's market share in the U.S. smartphone market surged from 23% to 31% in Q2, while Apple's share dropped from 56% to 49%, indicating a renewed competition between the two companies [6] - Tesla is offering significant discounts to UK leasing companies, with rental costs for its electric vehicles down to just over half of what they were a year ago, in response to declining sales [7]