When I was a Market Maker years ago, the terminal that we used to make markets was called a level 3 terminal....looked the same as level 2 but had some other functions that were used to put customer orders in. One guy might have anywhere from 2 to 100 stocks that he made a market in and would have to monitor and move his bid and offer in those stocks. You could move back and forth with tabs between stocks...so when you see UBSS moving on your level 2 box, it is the UBSS market maker putting his price in with level 3....