Elon Musk make some people panic and change how market price from green to be red and almost time he made red market to be green, many people make him as key how bitcoin and altcoin price going on, I think when trader and investor never heard about what he said exactly when make bad tweet about bitcoin or altcoin never any impact to make bitcoin dump or altcoin going to lower price.
Elon Musk is an extra person in this market, he has a very strong influence on this market. Because of his posts, the price of Bitcoin collapses, and after that the entire cryptocurrency market falls, and Bitcoin at one time hinders the development of other promising projects, as it pulls their price to the bottom.