Investing.com - Cryptocurrencies may be on the rebound after a brutal early year correction, but one investment bank says the worst is yet to come.GP Bullhound predicts cryptocurrencies will experience a correction of up to 90% in the next twelve months, with very few of them surviving the event. Once that survival-of-the-fittest scenario is over, however, growth prospects for the survivors will be unprecedented.The firm says the "mass market wipeout" will be critical in cutting through the hype of digital currencies. There are now more than 1,700 cryptocurrencies, many of which are worth pennies and have marginal trading volume. Bullhound predicts that Ethereum, now a distant second to bitcoin in terms of market cap, will vault to the No. 1 position.