Had an interview with them. What it involves is a maths test, which is extremely hard calculations like 554 x 89 WITHOUT being allowed to write anything down of any sort on the paper (It all has to be in your head) in five minutes.
Then your shown two graphs of an equity, bond, etc/whatever and asked to work out whether it is going to go up or down. The correct answer for mine was 'neither' as the messages were mixed in the graph.
Finally a normal interview style question with why do you want to be a trader, times you have been under pressure, etc.
Any other questions pm me.