I check their movement in terms of value. Also, I check how they contrast with Bitcoin's movement. There are so many altcoins that could have a big potential; however, unfortunately, they can't hold their ground against high-tier altcoins and Bitcoin, whenever, those assets go up, most altcoins go down. So, I check for those that can endure like Ethereum. Another is the market cap, if it has a large market cap, then there would be more chances to acquire it for value.