Group One asks many Math based probability questions as well as questions that about one's desire to be an equity options trader and desire to trade for Group One specifically. The questions start out qualitative and move towards quantitative very quickly. The probability and brain teasers are meant to test a candidates thought process and ability to act under pressure.

Multiple weeks, phone screening then two rounds of interviews several probability and mental math questions, nothing difficult just basic statistics and classic questions. Prepare as you would any other trading interview