I had also the idea of just placing for fun a very low order ;-) These exchanges are are not regulated like a stockexchange where the trading of a rapidly dropping stock would be postponed if it reaches, lets say -20%. On a cryptoexchange is no such safety measure. So dramatic crashes can occur. I think these exchanges will look what to do with this issue...
So till then, if many people would place lower buying orders, because they see an opportunity, it could create a "safetylayer" on the exchanges so crashes might be featherd and not so extreme. Topic: selfregulation of markets by opportunity ? What do you think ?