I maybe wrong offcourse, but buying now BTC is crazy. It is up from 3400$ to 7300$ just in month!
A: It could hapen sell of before the fork. Some traders will take money from Bitcoin at ATH
B: It could happen sell of after the fork, so people who now sold alts will return back.
In my opinion you should buy alts now and get your profit in short term.
I think it is better for you to sell 1 BTC you owning for some stable alts. And do not sell alts at least when they are bleeding.
If you want minimalize risk look at ETH/BTC pair. I do not know for sure, but it seems ETH//BTC ratio will increase and you could made much more BTC in the end. Just look in a weekly graphs of ETH/BTC..it is almost at the begining of this year. Definetly it will goes up. I wish I could have some BTC, but I am allready out of it in other projects.
I do not recomend to you wait till fork happens.
Also in short term you probably will lose money if will buy BTC for your alt now.
Technicly BTC is overbought and if it will grow more it will be suicide. I think it maybe good starting point to sell your BTC to alts now.
Just choose good alts, not shitcoins.
In my opinion even a daytraders must not buy BTC now. Short term they will lose money/alts