Local time Friday, the U.S. three-day index collective plunge, in which the Dow plunged once more than 2.4%, the S&P 500 index intraday fell more than 2.6%, the Nasdaq fell once more than 3.4%. "Technology stocks seven sisters" total market value of 14.74 trillion U.S. dollars, while July 3 the same day the data for 16.40 trillion U.S. dollars, nearly a month in the market value evaporated 1660.582 billion U.S. dollars (about the people's city of 11.9 trillion yuan). After the Federal Reserve's latest interest rate resolution chose to keep interest rates unchanged for the eighth consecutive time, the United States then released a series of economic and employment data, triggering the market's concern that the U.S. economy may be in recession, leading to a rise in the risk of a hard landing of the U.S. economy, triggering large-scale risk aversion.