Many people believe that a secure investment is to hold the bitcoins. No, bitcoins is money. Like as fiat money his price has up and down. Bitcoin's drawback till now is the big volatility compared to fiat money. This may be change in near future as the maturity of bitcoin increases over the time. Investments is the same as fiat too. Instead of deposit fiat you deposit coins. The same with withdrawal.
If bitcoin is experiencing price swings relative to any other currency, that makes it an opportunity to increase your value, regardless of whether you consider bitcoin to be money or not. Those two things, bitcoin being an investment and bitcoin being "money," are not mutually exclusive.
They are both currency and investment for me, but I am taking it more like an investment as the price swings big and I can predict the movement to make money in trading, in addition I can hold it for longer investment.