waverider, with all due respect, this is so multifaceted that to think it is all/mostly/some MM manipulation is a bit of a stretch.
DD is right re: daytraders of course. They have no loyalty, misplaced or otherwise. Truth be told they clean up every time we get a smiggin of news. Wavoids but it, they sell it.
Add to the mix the shorts, the long longs, newbies, and pros and you can't really say it's any one thing.
DD is right on imo
Good luck