There is a lot more fluctuation in altcoin price that in Bitcoin price. With that fluctuation risk improves. Altcoin price also depends a lot on Bitcoin price, therefor there will be change in price beforebitcoins segwit. I think that now s good moment to buy alts, because as closer we get to segwit more and more people will sell BTC and buy alts. With that price will rise, and in that moment it will be good to sell. That is my opinion at least.