Higher demand and market volume of the altcoins are essential that makes the price grow higher.
Altcoins have higher demand based on the true values of the project. Users buy altcoin based on the realistic use case of its project and the exchanges it listed. The project should be transparent to their users and needs constant improvement on its platform in order to serve better. The price of the coins does not depend on how much followers do you have or about the community hold, it purely depends on the integrity of your project.
The last is to hold and keep said altcoins for long periods of time in the hope that they will appreciate significantly in value, either by storing them to make a profit.
All these little things makes a bigger difference.