Let's just tell the acausal trade story in terms of extreme positive utility rather than negative.
Putting it simply for the purpose of this comment: "If you do what the future AI wants now, it will reward you when it comes into being."
Makes the whole discussion much more cheerful.
Suddenly I find myself confused. Why is this acausal?
Suppose I buy shares in a company that builds an AI, which then works for the good of the company, which rewards share-owners. This is ordinary causality: I contributed towards its building, and was rewarded later.
Suppose I contribute towards something other than its building, in the belief that an AI which will later come into being will reward me for having done this. Still doesn't seem acausal to me.
Suppose I believe an AI is likely to be built that will conquer the world and transfer all wealth to it...
Todays xkcd
I guess there'll be a fair bit of traffic coming from people looking it up?