Already in many sources they explain:
1. Power outages in the Chinese province of Xinjiang, which led to the loss of many industrial miners from the network, began on Friday, but this effect fully manifested itself later.
2. At the same time, there were still unconfirmed rumors that US regulators may start an investigation into unnamed large financial institutions for money laundering in cryptocurrencies. This led to a panic in the market and a massive liquidation of positions on the exchanges. Bitcoin was above $ 62,000 on Saturday morning, and set a local low of about $ 51,500 early on Sunday morning.
Two reason that might be confirmed as the cause of the decline in bitcoin price this week. But for whatever reason, I don't think bitcoin need good news or bad news to go up or down as it's a free market and it's up to the trader himself. The trader panic lasted for a moment before everything recovered.