If the prices of the coins are crash, there are some ways to get our money back. First, getting the money back sooner but we must lose probably half or other nominal at that time. It means that we sell the coins in that crash price. Alternatively, we can get the money back at least as our capital or higher if we can be more patient to hold. Just pick your choice.
When the cryptocurrencies crash, urgently stop to trade. Just take a pause and simply hold Bitcoin and altcoins. The market is not stable at all, and I am mostly involved in the other activities - waiting for the changes.