1) easier said than done - in general these are often OTC markets without clearing houses - that being said not insurmountable difficulties but not zero-cost either. 2) the previous days trades are backward looking, not forward looking. What’s the big deal you say, it’s just a day? We’ll think about driving by using your rear view mirror — you do fine until to hit a turn then things get a little sketchy, and a sharp turn can kill you.