Because people are not getting what they were expecting at this point of time. Before 6 months from today People were expecting that bullrun will start In the month of November but nothing is happening infact market is struggling very badly right now. That's why most of the people are holding their investments and waiting for the bull run to make maximum profits.
People need to sell everything and leave the crypto market. Those who are behind the fall in prices will try to force more people to sell their coins.
They are doing it through spread fake news and FUD. Look at faketoshi and how that guy was created FUD to the crypto anytime. Most of FUDders wanna see the crypto to be plunged to the bottom price.
But the panic sellers don't have good mentality. THey always try to follow that shitty advise.