In your opinion what are the reasons that let someone start dumping his bitcoins and walk away ?
I personally (and this is just my opinion) that it's more panic then simply his need of money or something else , as we saw on the BitcoinXT last time , people started to panic and simply sold their bitcoins and that caused a drop in the price .
Maybe because they are afraid that their investment will lose its value, that's why before it happens, they will sell their bitcoin as long as they have a small profit from it. Unfortunately, this reason makes the price to fall down as it decreases the demand. we all know that if the supply is higher than the demand, the price will get lower as expected.