I think if you are a good trader, it is better to buy when the price is low and sell when prices are high and so on. But if you are a bad trader then it is better to hold it for get profit.
I would say that a good trader will always know the importance of an asset and if it comes to a technology that has survived tough and red market and still claims a big portion of the market, I do not think he would sell away his coins no mater what the market condition are.
Bitcoin technology will surely bounce back and this is the beauty of the crypto market. No one expected it to touch the $20000 figure back in 2017 when it did and multiplies the worth of so many portfolios.