Segwit2x is a proposal that was intended for scale solution, to upgrades the bitcoin protocol which will be deployed based on Segwit 2Mb proposal.
According to New York Aggrement on May 2017 as the first time Segwit2x being planned, Segwit will be activated at 80% threshold signaling at bit 4 and upgrade to 2Mb (hard fork again) on November (if I didn't miscalculate).
How segwit 2x affect bitcoin price? You should know there are several advantages of Segwit, you can read in here
https://bitcoincore.org/en/2016/01/26/segwit-benefits/All those advantages expected to upgrade bitcoin and makes people could transact bitcoin easily than before.