The rebound of altcoins is mostly due to significant declines; this time, the altcoins that have doubled in value have all dropped by 90%. Similar to junk stocks in the stock market, they suffer the most during bear markets and rise the highest during bull markets.

Through this logic, you can look for any that are still at low levels and have not increased. Some altcoins may have been abandoned by their operators, and not all low-priced ones will rise.