The second reason to buy the most liquid coins is that there are risks of scams. When you purchase Bitcoin you are sure that you will be able to sell it to somebody later. However, when you buy X coin, which is not as liquid and as popular as Bitcoin is, your risks are higher as everything depends in this case on the project, its team, goals, roadmap, background etc.
This analysis can be done by searching for information on the number of transactions performed per day and the investments that banks or financial institutions have made in Bitcoin companies. In addition, information on the growth of companies of Bitcoin and blockchain can indicate a possible growth of cryptocurrency, as well as new use cases such as international payments and payment processors.
Never put all your eggs in one basket. Diversify. While the potential to earn more is increased with the amount of money you invest into a coin, the potential to lose more is also magnified. Another way to think about it is to look at the cryptocurrency market as a whole; if you believe that this is just the beginning, then more than likely the entire market cap of cryptocurrencies will increase. What are the chances that this market cap increase will be entirely driven by one coin vs. being driven by many coins? The best way to safely capture the overall growth of cryptocurrency is to diversify and reap the benefits of growth from multiple coins. Also, fun fact — Between January 2016 and January 2018, Corgicoin has increased by 60,000x, and Verge has increased by 13,000x. During the same period, Bitcoin has increased by 34x. While you would have gotten impressive gains from Bitcoin, expanding into other coins could have landed you potentially larger ones.