Last week bitcoin try to break $4500 about three times but to no avail! I think above $4500 is possible before the end August as the momentum is very high and bitcoin Cash has rise significant for the past two day to close at $870 yesterday, I think very soon bitcoin Cash traders will start to take profit and fund will flow back to bitcoin.
Have you recall the $3000 wall? Bitcoin had a hard time scaling that wall and it even took a while before Bitcoin completely surpass that mark. This could also happen on the 4500 dollar mark. Bitcoin soared very high just recently and continuously attaining new ATH is not too healthy for Bitcoin.
BCH holders will continue to hold BCH, they can clearly see now that BCH can grow even higher so why trade it to Bitcoin when they can hold both coins in order to gain in both coins.