I'm not sure if I agree with the ethics of selling security exploits, but it's a world I know very little about. You seem knowledgeable, is there any more infor

I'm not sure if I agree with the ethics of selling security exploits, but it's a world I know very little about. You seem knowledgeable, is there any more information you could share about the business and culture of selling 0days? Like, how many people are doing that full time now (dozens or thousands?). Why do you think that the market slowed down, and do you think that most of the security hackers are trying to sell exploits to the responsible parties or do they expect most of them to go to government and other black hats? Sorry for the questions, no contact info in your profile. Answers from anyone would also be appreciated.