I think things are not being interpreted correctly here. If the AH trading volume were stretched across several hours, I'd buy into it but not when it happens within mere minutes of the closing bell.
What I believe we have here is pent up trades that were officially recorded in a few minutes of the close of the session and not more.
Market makers aren't always playing tricks on us and sometimes we'll read things into their actions, assuming without corroboration.
It is more than likely that there were some "golden crosses" happening behind the scenes. This could include $15,000,000 worth of cheap units the company itself bought. The MM, of course, becomes the middleman working the deals as they are part of the ongoing auction process. Crosses occur when the MM has buyers and sellers, usually interested in larger quantities to trade, and these deals don't show up publicly until the final tally must be posted---ordinarily within ten minutes or so following the session close. I do my own tally daily and for this reason I don't record the day's numbers until fifteen minutes or so following the closing bell. I do this for the sake of accuracy and many, many times I've seen my tallies change at least fifteen minutes after the bell.
HOWEVER-- (caps intended!)---you are unquestionably right about something going on---no doubt about it. Yesterday's volume was four and a half times that of a typical trading day of late. As meticulous as I am about such things, this flew right past me. So I'm excited now, as are you.
There are many investors (I used to be one, myself) who tracked volume shifts through the auspices of Barron's and subsequently invested where sudden momentum swings were especially notable over the course of a full trading week. Seeing this massive increase in volume has me thinking as you are.
Monday might make us all a bit richer.
