Paula: Clearly it was a seller that took GZMO down. Look at your time and sales screen between 12:15 and 12:38 PM EST and look at who the Ax was. If you know how to read T&S, I'm sure that you'll see what I mean. And, yes, some investors are ignorant enough to sell during lunch hour (he/she checked their computer during lunch, saw that GZMO was down on the day, panicked, and put in a sell/market order. It did, of course, have the effect of running the stops and perhaps a few MMs seized the opportunity and jumped on board as well. As long as MMs are allowed to short on the downtick and trade at 15:1 leverage, running the stops will continue to occur with small, low volume stocks like GZMO.