At least, we can reduce the amount of loss even with selling in this period if we holding good cryptos like BTC and ETH. It less likely to get low and have a good potential to come higher after all bad things blow over.
Yes, if for the time being it's better not to sell first because the price of Bitcoin and Ethereum is in good condition and always has a good increase, and I think people who don't have the chance to buy BTC and ETH when the price is still cheap will feel a little sorry to currently.
why not sell? it's in good condition to make money from ethereum or bitcoin. every investment has a plan made from scratch. when it is profitable or planning has been achieved I think there is no reason not to sell. never be greedy, or regret what happened. The altcoin is a lot of red right now, why not try your luck right now.