It depend on whether you want a long term investment or a short term. BTC is perfect for short term ones with the price fluctuation. Also, if you managed to buy early it is the wisest to keep your investment in place. Although, now it is a good time to invest in alt coins too, becase the prices are low enough to risk placing your money in them.
Majority of altcoins now are very cheap, this is a great time to buy if we can analyze that the price will rise after the price of bitcoin will be back to normal.
Now, investors are still busy buying bitcoin to avail on the bitcoingold but this will end after the fork and everything will be alright and altcoins will be up again.