What can we say is responsible for this massive movement?
The ideal word would be: "disillusion".
I will explain better, in the past years we had no regulations, practically governments ignored bitcoin. many people bought bitcoin and many other people were very optimistic about the future of bitcoin and the price of bitcoin did not stop rising, could have some falls, but in the end the price did not stop rising, it happens that the bitcoin price went up so much that caught the attention of governments that started to implement unfavorable regulations for bitcoin and at the same time the price of bitcoin could not keep to the level of $ 18000, causing the price to drop to $ 6000 and many people lost money in that process, with those losses of money people left the crypto world. See the price that all altcoins had in May and see their current prices, you will see that the losses are very high.
Some big whales dumping.
why would these supposed " whales " would do that?