It is not advised to buy on July 31st, may be a day before that or two. You need to have all your stash on a wallet but segwit. The price will definitely rise and it'll be a new life for all the Bitcoiners here. Buy as early as possible and hold them well.
It is best to buy before July31 though we cannot predict the price of bitcoin. These past few days bitcoin has downtrend and today it seems recovering. I dont know if this is stable or what but the fluctuation is normal. So when dump buy if you have funds and hold.
Don't let some trap recovery price make you buying and take loss, use your brain and analysic mentality of trader on market in some days. They are scared status SegWit2x and only when have some good news about SegWit2x can success, they going to buy very fast but this not is stable, just temporary and can't helps the price of Bitcoin can recovery at now!