If you are in the minuses, you have your own, and not borrowed money, you do not have a shoulder and you believe in the future of the crypts - just cross this fall. You lost the time, but did not lose the game. Forget the time for the market. Loss you will appear exactly when you fix it. Now you are just an investor. For you it's a good time to step aside and think with a sober glance at where you made the flaws. The market is cyclical. Believe my experience. After the falls there is only one way - growth. It can be long or fast, painful or enchanting. But in any case, to the right. If you believe in what you have invested in, wait and do not be nervous.
What are you telling is true if your first plan is really for investment. But if you're trader first on hand and you lost 50% of your portfolio I think there's something wrong with your trading plan exit strategy. 15% lose in the portfolio is so much to bear as a trader.
I think the cut lose should be set at 10% minimum and 15% maximum to maintain overall standing for the year. But of course this strategy vary depending on risk appetite of the trader or investors. Besides no perfect trading plan out there in the market what We only have is our personal experience.