It was very straight forward, I applied, got called in. First asked about behavioral based questions. Tell me about yourself. Why trading? Why Group One? talked about experiences on resume, then they asked me mental math problems. The whole process lasted around 30 minutes.

Contacted the recruiter with my resume and set up an initial phone interview. This was behavioral with a few easy math questions at the end. Lasted around 30 minutes. After that, had an additional phone interview with managing director. This time was straight behavioral, again around 30 minutes. Both interviews were very conversational, not stressful at all. The questions were not designed to trick you.