What i read was that Segwit will lock in at about august 10? Is that right?
It's August 8 or 9. You can see a countdown here:
xbt.eu. Their exact estimation is:
Lock-in threshold expected at ≈Tue, 08 Aug 2017 19:11:58 GMT
I don't think there are yet many big blockers who are making trades in the market until it could be completed.
You could be right, maybe big blockers are waiting with the BTC dump until a higher price has been achieved because of the Segwit lock-in. That would be a "smart" move from them - it would mean that they are not trying to harm Bitcoin but to get maximal profit. Totally legit if you ask me.