"UASF is short for "User Activated Soft Fork". Its specification is described here.
It tries to force the activation of SegWit which is currently (~30%) unable to reach the required activation threshold (95%).
Between August 1st and November 15th, UASF nodes will consider all blocks invalid that do not explicitly signal support for SegWit, thus creating a fork. Within that fork, support for SegWit will be 100% which in turn triggers the activation threshold of SegWit (95%)."
https://www.reddit.com/r/Bitcoin/comments/64jky9/what_is_uasf/
If soft fork happens successfully, then price willl rise , if not , btc price will fall hardly .
It's a gamble
What do you think ?
The UASF is one of the highlight events that are being waited by the majority and big bitcoin holders, players and exchanges. If UASF will be implemented it will bring bitcoin into another level. With UASF activating Segwit, bitcoin may improved a lot and that will become stable since transactions will be confirmed faster. If this activation will succeed we will hope to see that many big companies will be attracted to accept bitcoin and integrate it into their system. This will make bitcoin leap and we will expect a possible major inflation when that time comes.
If Segwit activation will not be implemented we can expect two things its either bitcoin will stay the same or there will be a possible crash of price/value.