I disagree. The Segwit fever is only beginning. BIP91 got approved without problems, but many people have distrusted the miners involved in the New York Agreement - they thought they could go back and continue to block SW, or even support Bitcoin Cash after the fork.
Now Bitcoin Cash had only 3-4% hashrate support (no, Jihan didn't participate!) and every day it's less likely that Segwit will fail. If we hadn't the August 1 split event (which many people thought of being bearish, because of possible dumps of "big blockers" that went all in in Bitcoin Cash) then we probably would already have passed the all time high. The big blocker dumps perhaps will continue some days more, but around August 8-9 (when Segwit is about to lock in) I expect a strong upmove and a new attack on $3000 USD.
So in my opinion it's time to buy. But as ever - only invest what you can afford to lose.