Bitcoin has developed incredibly quickly. In the eight years since the cryptocurrency was launched to a (mostly) unsuspecting public and financial market, Bitcoin has hit the mainstream, its value has increased more than a thousand-fold and people everywhere seem to be talking about it constantly. One side effect of this incredibly rapid growth is that we don't yet know where Bitcoin, and cryptocurrencies in general, sit in the world of financial investments. There are several places where Bitcoin could end up and, in this article, we're going to take a look at the options.If Bitcoin values eventually become high but relatively stable then there's a chance that it could become a popular reserve investment. As with gold, there is a chance that Bitcoin is where investors will flee when more traditional investments like stocks and shares start to lose their value. A key sign that this is happening will be governments starting to build up massive reserves of Bitcoin. While this would be good for the currency's long-term prospects, it could lead to some of the pioneers getting out of Bitcoin.Bitcoin could move into the world of the Forex trader and become another currency in the basket that they trade. This would imply that there is some risk of Bitcoin fluctuations but that there is general confidence in the integrity of the currency.Bitcoin could remain roughly where it is today - a high-risk investment for traders hoping to make a lot of money but accepting that they could lose a lot too. If the wild 10% daily swings in value continue, Bitcoin is likely to remain in this position for some time. Bitcoin's first eight years have been a rollercoaster and it appears that the next eight could be similar. It could be some time before we know what the long-term future of Bitcoin actually looks like.