Hi! Yes you are correct, great point. In a real world scenario, we would have to consider the price prior to market close (as of 3:50 pm for example), to calculate the updated features and give the agent ample time to make a decision same day. Or utilize the T+1 open prices as exit points. Either way, we would also have to consider some error to account for the fact that we would need a market order to guarantee exit (so our exit prices may be slightly higher depending on the spread). Tried to keep things simple for demonstration purposes, but regardless i should have mentioned that in the article, so thank you for pointing that out!