It would be more prudent not to make any transactions until everything is stable after the hard fork. We do not know for how long, but keep all your Bitcoins in a wallet for at least 1 month to be safe.
Rushing to dump B2X for maximum profit is a risk as all your transaction could be replayed in the original chain.
This is a great concern actually but now its not even sure that the fork will happen which I expect that the moment it is confirmed that its going to happen, the issue of replay of original chain would have been settled. Waiting one month before acting could mean a lot of loss for someone who is bent on making the maximum profit which is dependent largely on timing and if missed, it might be difficult to get it back.