[zarzavat]

That's not how insider trading works though.

Let's say that you know that event Y is going to be announced that will make event X more likely. Before Y is announced you buy shares in X on a prediction market or buy some asset that has price correlated with X. After the announcement you liquidate your position and pocket the difference.

Whether X actually happens or not is irrelevant to you. All that's relevant is the timing of the announcement of Y and the directional effect of Y on X.