When we sell altcoins on trading, we may sell in many separate orders. When there are large amount of of the altcoin, it is really necessary to do so.
Sometimes the price of an altcoin may plumb so rapidly and suddenly crash. Certainly we want to sell off the altcoin to gain profits before the crash.

But then I discover the difficulty that might be faced when selling large amount.

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?