美东时间周五，美股尾盘跳水，道指收跌逾900点，纳指收跌3.8%，标普500收跌4.34%。迪士尼、3M跌超9%，领跌道指，苹果跌超6%。三大股指单周跌幅均创2008年金融危机以来最大。
美国三大股指分时走势图。来源：Wind
具体来看，截至收盘，道指跌4.55%报19173.98点，标普500跌4.34%报2304.92点，纳指跌3.79%报6879.52点。本周道指跌17.3%，纳指跌12.64%，标普500指数跌14.98%。四种期权产品同日到期使市场剧烈波动。
美国大型科技股多数收跌，亚马逊跌1.85%，奈飞涨0.24%，谷歌跌3.91%，Facebook跌2.22%，微软跌3.76%。
美国航空股反弹，但多只美国大型航空股今年已跌去六成以上。美联航收涨超15%，但本周仍然累跌超41%，今年迄今暴跌72%。达美航空收跌0.74%，本周累跌超44%，年内跌超63%。美国航空涨0.78%，今年累跌63%。
热门中概股涨跌不一，阿里巴巴跌0.07%，京东涨1.21%，百度跌1.07%；人人网涨41.82%，趣店涨35.25%，万达体育涨11.81%，蔚来汽车涨0.63%；趣头条跌10.11%，蘑菇街跌9.85%，斗鱼跌9.83%，拼多多跌0.68%。
个股方面，苹果跌6.35%，报229.24美元/股。据媒体报道，苹果5G版iPhone仍将在秋季发布，尽管其量产直到5月份才会开始，未来仍可能会出现延迟。
消息面上，美联储和澳大利亚、巴西、丹麦、韩国、墨西哥、挪威、新西兰、新加坡、瑞典等九国央行建立临时美元互换机制。而在此之前，美联储已经和欧洲央行、日本央行、英国央行、瑞士央行、加拿大央行建立此类机制，以提供美元流动性支持。
货币互换协议是在必要时将本国货币交给对方国家中央银行，并允许借用对方国家货币。美联储在2008年金融危机时与全球14个国家签订了货币互换协议。
欧洲三大股指收盘集体上涨。英国伦敦股市《金融时报》100种股票平均价格指数20日报收于5190.78点，比前一交易日上涨39.17点，涨幅为0.76%。法国巴黎股市CAC40指数报收于4048.80点，比前一交易日上涨193.30点，涨幅为5.01%；德国法兰克福股市DAX指数报收于8928.95点，比前一交易日上涨318.52点，涨幅为3.70%。
国际金价20日上涨。纽约商品交易所黄金期货市场交投最活跃的4月黄金期价20日比前一交易日上涨5.3美元，收于每盎司1484.6美元，涨幅为0.36%。
美元指数20日微涨，截至纽约汇市尾盘，衡量美元对六种主要货币的美元指数上涨0.08%至102.8293。
U.S. stocks dived late, with the Dow closing more than 900 points lower
U.S. stocks fell late Friday, with the Dow down more than 900 points, the NASDAQ down 3.8%, and the S & P 500 down 4.34%. Disney, 3M fell more than 9%, led the Dow, apple fell more than 6%. The weekly decline of the three major stock indexes is the largest since the financial crisis in 2008.
Time sharing trend chart of the three major stock indexes in the United States. Source: wind
Specifically, by the end of the day, the Dow was down 4.55% at 19173.98, the S & P 500 was down 4.34% at 2304.92, and the Nasdaq was down 3.79% at 6879.52. This week the Dow fell 17.3%, the NASDAQ 12.64% and the S & P 500 14.98%. The expiration of four options on the same day makes the market fluctuate violently.
Large US tech stocks mostly ended lower, with Amazon down 1.85%, Nye up 0.24%, Google down 3.91%, Facebook down 2.22% and Microsoft down 3.76%.
American Airlines rebounded, but a number of large American airlines have fallen more than 60% this year. United Airlines ended up more than 15%, but still fell more than 41% this week, plummeting 72% so far this year. Delta ended 0.74% lower, down more than 44% this week and over 63% in the year. American Airlines rose 0.78%, down 63% this year.
Popular Chinese stocks were mixed, with Alibaba down 0.07%, JD up 1.21%, baidu down 1.07%; Renren up 41.82%, qudian up 35.25%, Wanda sports up 11.81%, Weilai auto up 0.63%; qutoutiao down 10.11%, mushroom street down 9.85%, douyu down 9.83%, pinduoduo down 0.68%.
In individual stocks, apple fell 6.35% to $229.24. According to media reports, Apple's 5g iPhone will still be released in the autumn, although its mass production will not start until May, and there may still be delays in the future.
On the news, the Federal Reserve and the central banks of Australia, Brazil, Denmark, South Korea, Mexico, Norway, New Zealand, Singapore, Sweden and other nine countries established temporary dollar swap mechanisms. Prior to that, the Federal Reserve has established such mechanisms with the European Central Bank, the Bank of Japan, the Bank of England, the Bank of Switzerland and the Bank of Canada to provide us dollar liquidity support.
The currency swap agreement is to hand over the domestic currency to the Central Bank of the other country when necessary, and allow the borrowing of the other country's currency. During the 2008 financial crisis, the Federal Reserve signed currency swap agreements with 14 countries around the world.
Europe's three major indexes ended higher. London equities, represented by the financial times 100 stock average price index, 20 daily, closed at 5190.78, up 39.17 points or 0.76% from the previous session. France's CAC40 closed at 4048.80, up 193.30 points or 5.01% from the previous session, while Germany's DAX closed at 8928.95, up 318.52 points or 3.70% from the previous session.
International gold prices rose on the 20th. The most active April gold price in the New York Mercantile Exchange gold futures market rose $5.3 to $1484.6 an ounce, or 0.36%, on the previous day.
The U.S. dollar index rose slightly on the 20th, rising 0.08% to 102.8293 as of late New York.
