At 8 o’clock on April 21, Beijing time, the ChaiNext 100 index, which reflects the overall trend of the cryptocurrency market, reported at 632.94 points, down 3.96% over the past 24 hours, with a turnover of 85.055 billion U.S. dollars, and an increase of 11.66% over the previous 24 hours. Four of them went up and 96 fell; the ChaiNext 5 index, which reflects the performance of the blue-chip cryptocurrency market, reported 548.70 points, down 3.86% in the past 24 hours, with a turnover of 68.296 billion US dollars, a 14.26% increase from the previous 24 hours; the Bitcoin Bubble Index ( BBI index) reported 74.99 points, down 1.39% in the past 24 hours; USDT OTC Index (USDT OTC Index) reported 101.37 points, up 0.51% in the past 24 hours. Yesterday, the US crude oil May futures price fell from an open 17 dollars to an intraday -40 dollars, which was also the first negative price of crude oil in the history of the United States. The exchange CME has predicted that this phenomenon will occur more than 10 days in advance, and reprogrammed the trading system to handle negative price orders. After falling to a negative number, VIX rose and the U.S. stock index fell rapidly. As a result, BTC plunged to $ 6,750, and other currencies also went down. The average decline of the top 20 mainstreams was 4.5%.