Did anybody lose because you could not sell off all the coins in time before the crash?
Are people really willing to buy from you when the price of the altcoin plumbs so rapidly that people may see the risk of crash and that you fail to sell off your coins and finally have a large amount of stagnant coins in your acc?
All traders and holders will lose when the market is crash or correction, and when the market is like that it is better to leave the market or set a stop loss in anticipation.
If my advice is not to sell your coin to someone else, because usually the correction or crash is only temporary, or if you want to sell it, you have to see if your coin has potential or not, if it doesn't have potential it is better to sell.