To use Bitcoin as a currency is allowed however to use bitcoin as an investment vehicle it would be associated with kimar or gambling. That is very clear when currency becomes a commodity then the price fluctuates a lot, not because of the strength of the currency but because of speculation by the speculators. Like when bitcoin investment was open instantly the price went up because people started to trade in it and not using it as a currency. Most countries around the world started accepting bitcoin because of the easy trade and not because of its currency, just like stocks. So it increased the price and for sure that price is not representative of the underlined value. Because of that many people have lost what they invested in Bitcoin.