I just read Satoshi Nakamoto's whitepaper, and in that it states bitcoin is designed and meant to be a decentralized form of electronic currency. But even though this was the original idea of bitcoin, why did it gradually become a trading asset, and something whose value frequently fluctuates? Will it become stable if it is used by a lot of the world?
The idea was to have it be a means of exchange. But it soon became evidently clear that Bitcoin has the properties of sound money, hard money... much like Gold. Gold was also used as a means of exchange, but eventually that evolved into paper notes and coins to help with it's divisibility and portability.
In any event, hard money (Gold, Bitcoin) also have the properties needed to also make it a good "store of value" - and this is something that appeals to investors looking for a place to store their money and where it won't go down in value like fiat currency.
Because in the scheme of the entire world financial market Bitcoin is still very nascent and small, it has more volatility. But I do believe that if adoption and growth continues, it should stabilize a bit more and become less volatile.
Just my two Satoshis!