Just hold your altcoins.Earlier,it was expected that most people who slod out their altcoins and bought bitcoins for getting free BTG coins during hard fork would very soon sell their bitcoins after getting free coins and buy altcoins which would trigger altcoins price.

But unexpectedly,those people didn't sell their bitcoins and they might have thought that yet another hard fork due to segwit 2x activation is very near and so just to hold bitcoins.That's why,altcoins price have not increased.

But very soon,after segwit 2x activation,they would start selling their bitcoins after getting free bitcoin segwit 2x coins and would start buying altcoins.At that time,altcoin prices would trigger and you could sell your altcoins at that time.