Jump Trading Software Development Internship interview questions

Met them at a campus career fair. I approached someone to talk about opportunities and such, and after a little bit they gave me a brain teaser. After I correctly answered, they offered me a next day interview. At the interview, they jumped right into a coding question where I was up on the board coding a simple problem. After I was coding that, they kept chiming in with suggestions and other possible implementations. I coded everything right and answered their questions correctly, but still did not get an offer for a second interview.