I would not take risk on investing it anywhere else and would directly buy bitcoins with that amount and wait for the price to go higher and would sell them when its giving me enough profits and buy again when price falls in future and repeat the same cycle again and again.
Smart and safe decision means less but sure profit. If you aim for higher then you need to consider trading with altcoins, look what ETH did it, look now dash, there is potential in every coin, and even thou most of them are new remember that same thing happen to bitcoin, in beginning some people were saying how btc is a scam and look where is it now.
Buy 1.5 btc and put it on saving, but rest invest in several altcoins, take a chances to make good profit, cause if you don't buy on time you can regret later.