Window Dressing & Setting the Open Now why would you sell a small amount of shares? 1K near the the bell, $160 exactly, if you could have sold it at a higher price earlier in the day? Really, what's $160 worth. Not much to many on this board however its affect on price confidence the next day at the opne might be significant. I am very familiar with trading floor and trader tactics having worked there. Its simply taking advantage of low volume to push the stock lower also known as "setting the stage" for the opening the next day. Also prefessional traders are for hire....and will do as they are instructed by whatever party contracts them. If Petrostar gets an institution behind them soon, through an agreable deal, then the institution will support the stock by instructing its desk traders to do so. Its the same as running the stock up or down on consecutive100 share trades with a non-penny stock. Here, you need a minimum of 500 shares to qualify as a trade. All stocks have players with different interests on both sides of the trade. Very small trades at the end of the day are a classic sign of professionals or interested parties at work.