Hi, I am a student and head of small trading group from Cyprus. I am interested in extended-hours trading on ATS and US stock exchanges. I was surprised when I found that Reg NMS rules are not enforced during pre- and post-market sessions. I found a large number of ATS trades during extended hours. But I have read practically all existing Form ATS and can’t find any of dark pools that allow matching orders during extended hours. Can anybody explain whence all these ATS trades come and how these transactions occurred? Also, I find many ISO trades during the extended-hours session. What the point of the ISO orders if Reg NMS rules are not enforced?