Thanks RickDipper! That is very useful info. It confirms that...

Thanks RickDipper!
That is very useful info.
It confirms that these brokers buy and sell in very narrow price ranges, that they make lots of buy/sell trades within those ranges, and often in quite small parcels.
Over an aggregate of 4993 trades in June representing 981000 shares this suggests that only 1450 shares actually went outside this pool or have not yet been re-traded. That is 981000 shares traded at between $18.98 and $21.27.
That is an awful lot of paper shuffling! And an awful lot of trading commissions if these trades are on behalf of chargeable customers!