It's a speculative myth where 911 means news coming..
It's something tossed about the internet saying market makers send signals to each other and that is supposedly one of them but it's never been proven.
I've known people to deliberately buy that many shares to see the reactions of other posters.
People say that when you see a 911 trade. Its MM's telling each other that News is coming out soon! Thats what people say and there is No actually proof if that is true but ive seen it before with other stocks! We will just have to wait and see for ourselves to see if its true or not. It would be SWEET though if we receive news tomorrow though! =) $P$
100 > I need shares 200 > I need shares badly but dont take it down to get em 300 > Take the price down to get shares.... 400 > Trade it sideways based on Supply and Demand 500 > Gap one way or the other, usually to the direction of the 500 trade. Sometimes -if in the middle -keep the price right where it is 911 > News incoming
From what I've experienced (which is little), it's MM code for "information" (news) coming soon. From what I've seen, if you see the 911 trade on L2 near closing, the following day there should be news coming out. That's all I know. I've seen it before when others with L2 (I don't have it). Just my opinion based on some trading experience.