I can do a quick estimation of how many people actually attend Trade Day, as a TD attendee myself. According to my TD program book, the average time slot has 13 or so seminars. Most seminars have about 10-20 attendees, so that gives 130-260 total TD attendees who actually participate in the seminars and other Wednesday activities. If we add in a few more who only attend one or two sessions, maybe bump it to 300.
That seems reasonable to me as generally by 4 PM on Wednesday I recognize most of the other Education TD participants from previous seminars.
Therefore, if the bulk of the early access line is made up of TD people, most of them are not attending any of the actual TD events.