feltonW, re the small trades you asked about and their...

feltonW, re the small trades you asked about and their purpose

“Marking the close” involves buying or selling a stock near the close of the day's trading, with the objective of affecting the closing price. This might be done to avoid margin calls (when the trader's position is not self-financed), to help stymie a takeover or rights issue, to support a flagging price or to affect the valuation of a fund manager’s portfolio at the end of a quarter (called "window dressing"). A common indicator is trading in small parcels of the security just before the market closes, which results in a higher closing price.

cheers
orga