North Korea has been doing the same thing for years, and nothing has happened, and nothing will happen to cryptocurrencies. They just like being the center of attentions. But if anything were to happen, the markets will defininetly feel a blow and the stocks will take a big dip, but nothing major.
I can't really take the situation seriously. It's just the same old story over and over again. If something were to actually happen the markets shouldn't really be affected by it in the long run though. There might be a brief shorting period, but that's it. On the other hand, the stock market (tech) seems ripe for a retraction regardless of the North Korea buzz, so that's something to consider for those who have significant amounts of shares.