Optiver Quant Trader Intern interview questions

There are a few rounds. First round is an online OA, which is fairly straightforward, mostly games and some math problems, some mental maths, sequences and probability problems etc. The second round is an intro HR round, followed by 1-2 technical rounds before a final onsite composing of a technical, a behavioural and a desk shadow.

first round, a 30min betting game, not very difficult, will ask question along the play, I did pretty well on the profit and answering, but still got declined after two days, no idea why.