In the decentralized nature of the market, supply and demand is what determines the price, and therefore the factors that affect supply and demand are what make changes, but they are related to market capacity.

For example, in 2017, about several million dollars were enough to affect the price, but today we need several billions of dollars, and so the more market capacity increases, the fluctuations decrease because of the need for trillions of dollars to move the price 10%.

As for altcoins, and because the market capacity is small, it is difficult to predict the changes, which may be artificial (a million dollars may change the price a lot) and therefore the associated factors are more complex.