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.
The btc can lose its price, ok, but it's not going to happen soon, we don't need to fear bitcoins volatility, no chance to lose money holding btcs now.
Hard to find investments worthing the time you must give your money to them, so it's better to hold bitcoins or to do any other profitable activity. Investments offering 2%-5% monthly aren't enough, crypto-currency gives us the opportunity to make higher profit, enjoy it.