100million only equates to $800000 or 3.5% of the stock. That's...

100million only equates to $800000 or 3.5% of the stock. That's not much. I've seen day trader action commensurate to this many times before. If someone was accumulating a large position or trading one down, wouldn't there be change of substantial holding notice?
You are probably right though. Just seems to me most of it could be accounted for by smart players taking .001 cent arbs combined with other t+3 traders rolling over bets until the announcement.