I think because Friday is the weekend, this weekend a lot of traders are out of trading activity faster than usual, for example in Asian countries some brokers and traders will close their weekly trading activities as soon as the Tokyo or Sydney exchange closes, in the European market session, some brokers and traders will also close their weekly trading activities as soon as the london market closes, so that the volume of transactions and transaction activities will be different from the volume of transactions and transaction activities on other days.