Often, people make the mistake of following other people's projections about cryptocurrency dogmatically, which should not be so. Personal research and analysis is critically important. Yes, Prices go up, but as much as they go up, they come down too. Crypto-currencies are volatile assests. Here are the lists of some of the factors influencing Crypto-coins among all other factors:
1. The Law of supply and Demand
2. The News or Media
3. Regulations (Both Government and Economy)
4. Technological Progress
5. Fear, Uncertainity and Doubt (FUD)
6. Security and bankruptcy
7. Public interest / Societal Adoption etc.
Before choosing any coin to buy and HOLD for long, all these factors must be put into consideration. There must be enough checks and balances. Other people's opinion will not always work, but personal research will do more justice on the behaviour of any coin.