It is better to wait, while I do not think the price of bitcoin will go down much further and as such push the prices of all altcoins down, at the same time bitcoin has given us bigger surprises than that, so it is better to take your time and only invest in altcoins once you see an upward trend, it is true that if you wait until the trend appears you are not going to obtain as much profits but you are also going to diminish your risk and that is quite important as well.