How 'smart' do I realistically need to be?

[jayatenet]

I consider myself to be a 'average' high achiever. I got all As in high school, took many Aps, and 35 on ACT. However, that was all through hard work and I am not a mathematical 'genius' who is innately smart. Hence, I was wondering if I have what it takes to be successful in quant through hard work or if everyone successful in quant is a pure genius

 

[Andy Nguyen]

You just have to be good enough to get into a good master program, do well in interviews and get a job.
To look at the real world data, go to the Tracker and see the profiles of people who get accepted into the top MFE programs to see how you fare. Those are the profiles you compete with.
It's good to be a pure genius but it's not a requirement to have a successful career. Brain power is not the only thing that matters. Soft skills are just as important.