4 phone interviews plus 1 on-site final round. I was not impressed with hr as a couple of times they told me I passed the phone interview, that they would schedule the next interview within a week, and then they did not. I had to call them to schedule. Also, they did not call me once for a scheduled interview and had to reschedule.
Phone interviews are mostly math problems / brain teasers. No fit questions whatsoever.
For the final round, they give you a study sheet, and expect you to memorize the jargon inside out. You should be very fluent in their language (of trading). It is pretty difficult, so don't put it off till the last day, and practice. They give you a 100 poker chips and expect you to 'make a market on' various things, such as, sum of the face values of the next four cards flipped, sum of squares of the next two dice rolls, etc. You have limited time, so they expect you to think and ACT fast.
I ended up with ~140 chips at the end. I did not get an offer. I don't think the number of chips matter. I think they evaluate your personality more than anything else. I was not a good fit (I now think I was very risk averse, I only bet when I was very likely to win. That's why I ended up with 140 chips. It's no good though.), so I didn't get the offer. Overall good experience though.