Stop-loss kicked in immediately

Hello

I have not found information about which are the largest real-time bitcoin exchanges.

I assume the largest of them is Mt. Gox?

But what are the 2nd and 3rd largest?
An article about bitomat.pl said it was the 3rd largest market, is that correct?
Tradehill doesn't seem to be that big if you look at the available data.

Has someone information about that?