Whole thing depends on the market condition of cryptocurrencies. And If you look at bitcoin , when it's going to down then most of the currencies also turning to downing. When a cryptocurrency gets hit badly, the price of Bitcoin starts to fall, and all alt-coins around it start to fall. It because of the dominance of bitcoin in cryptocurrency world. And so now during the bearish season Bitcoin prices have fallen and all other coins have fallen in parallel.
Not really, what you mean about market condition is good and bad news. Good news doesn't always make Bitcoin price increase, same applies bad news doesn't always make Bitcoin price decrease. But in short term, it will effect the price since there's still many newbie and weak hand people. Just like now, there's many bad news around when Bitcoin price already go down 70% from the previous ATH, but it doesn't make Bitcoin price continue to decrease.
Acccording to my understand, there are many things that causes the dump in price
(it could be bad news, mining difficulty, 4years cycle, level of demand and supply)of the Bitcoin market, and it's not every time that the altcoin follows the market trend of Bitcoin
(this always happen when it altcoin season and it will happen soon) . However, the current dump in the market is due to the 4year cycles and every negative news create now is just to cause panic and to shake off the weak hands.