I met with one of the partners of DRW, and he was really cool and laid back. We started out with some fit questions that I thought I answered pretty well. But after I mentioned that I was taking a course on options pricing, the rest of the interview was him "teaching" me about American and European options (I had very little knowledge since I just started the class) and me drawing graphs of puts, calls, and some portfolios. It was not what I expected at all, since most people get math and probability questions. I was not asked for a second (final) round interview.