That is a lesson you can learn from any other dump we have witnessed in the market in the past, so while important I do not think it is related to the events that occurred this week, a more important lesson is to always keep your coins in a wallet only you control, because as we have seen no exchange no matter how big or how good is their reputation is worth of that trust, as they could always collapse out of nowhere and then make you lose all your money with no chance of ever recovering it.