I can only guess, but I think someone got in way over their head in the neighborhood of .50 and above, and then bailed for a end-of-year tax-loss.
Also, a well-respected investor that traded this ticker and $CMGO passed away in October. His family could be selling his estate for all I know. Probate lawyers don't care what you get as long as it pays their bills.
Just some guessing on my part while I've got all this time to watch my portfolio disintegrate.