The price and, ultimately, the charts on any given exchange are determined by the price of the most recent transaction. How can the prices of 100s of cryptos all move in the same direction at the same time?
Because all the coins in the crypto market are just dependent on whatever the price of bitcoin will be. Bitcoin is the driving factor in crypto, so whatever it’s price will create a huge impact on the rest of the coins. If bitcoin is bullish, most likely the whole market will be lively and bullish too. Same goes when bitcoin is bearish, the whole market will sympathize and end up being low priced too.
Altcoins will always rely on the situation of Bitcoin because as the king of all cryptocurrencies, it always dominates the market. That's the reason why most altcoins pump during the bullish season and dump along with the price of Bitcoin when the bearish situation occurs. But that doesn't mean that altcoins that follow the movement of Bitcoin are all reliable. You still have to be wise in choosing. The legitimacy of coins that we're investing in always matters because even scam projects go along with the value of Bitcoin.