BTG moves for now quite independent from BCH and BTC. However, they are all related. When bitcoin got its upward move, BCH goes down. Whenever BCH moves up, BTC goes down. But what about BTG?
What I assume is this:
BCH will be 50% of BTC BTG will be 25% of BCH BTG will be 5% of BTC
Remember: Forks are always priced in. At the moment of writing is BTG 345 BCH 1450 BTC 6300