number 3 is right. You are assuming that they were "pinged". There was no please explain notice posted from the ASX. If that was the case, from what we all know and is on the record, we could probably get the stock standard, that they have no idea why the price surge happened. THAT is the "usual" response to a standard speeding ticket, the no reply will be a dud.
BUT, for there to be an explanation, it would mean that the company requested the pause pending an announcement which is potentially "material", which they HAD to report anyway. That announcement could be very price sensitive, or a dud, DEPENDING on who initiated it. Sleep well, we "should" know tomorrow by 10 a.m. Let's hope that it's the former.