One could have easily put the blame on whale manipulation since the halving event is getting closer and like previously they're shaking the market to chase away weak hands to refill their bag with the hope of benefiting from the hype associated with the halving of bitcoin's block reward.

Although that's not the case since not just the cryptocurrency market is been affected but all other traditional market like stock makret, bond, commodity etc were all affected. The like of Gold, Oil, company shares etc all declined in price. Forex market was also affected as some currencies lost value.

Since the whole economy was affected than the trend of the day which is Corona virus would had obviously been the cause of the panic, people decide to take precautions measure since no one knew what was going to happen next, they're all cashing out their investment and probably storing more  fiat Incase if an economy meltdown.