Today I was patiently day trading a small stock "ISO" using DAS trader software when I noticed something I have never seen nor can I explain. So I am looking for anyone that could explain this to me. It happened 3 times today from what I could see. The first scenario was this: Stock was at Bid .35 Ask .37...All green buys at .37 going at this moment last was .37. Then during the buys the Bid went to .38 while the last price bought remained and continued at .37 and Ask was also .37 for about 1 min. Then of course the sellers got in and started dumping at .38 and the ask was then changed to .39. It was completely backwards from what I have seen in my experiences thus far. This happened 3 times on this stock. It looked like the price was being driven down or for some reason ARCA and NASD were buying up the shares at .38 while others were selling at .37. It was mainly ARCA that was doing it NASD seemed to follow later. What does this mean. I was reading in other news groups that this may have been some sort of PPS manipulation or a bear attack. Can shorts cause this? I thought that the books could be crossed but this just seems unlikely especially since it occurred several times. I also confirmed it on Ameritrades level II. Any input or references for research would be helpful. I need to understand this better.