Panic sell is big loss for the ones who own lots of bitcoin or other currency, it's much logical to sell little by little with sell walls. Instead of dumping the market and selling half of the coins for half price, also crashing the market..
What it happens is that people do not have a strategy when it comes to their bitcoin, having lots of money does not mean that you know how to manage it, selling for a price lower than the one you bought is a terrible mistake, it is better to hold, even if you have to do it for years since losing time is better than to lose money.
Sometimes you need to sacrifice in order for you to bounce back, those who understand how trading works are able to justified there decisions not because you sell your holdings to a much lower value means that you won't be able to recover sometimes buying back is also another set of strategy to gain back and start to earn again.