How influencial are the Red Mafiya (Russian) in global finance?

The more and more I read about this group of criminals, the more I realise just how potentially dangerous they can be. But along with savagery, Russian organised crime has the ability to be very sophisticated.

As I have read, they have managed to infiltrate the stock market, and are involved in some of the most complex bank fraud schemes ever uncovered.

My question is, how exactly do these groups get involved in these activities? What I mean is, do they know corrupt stock brokers on the inside, or the senior management at firms/banks? How do they make these connections? Also, why are these specific gangsters involved in such ingenious schemes? How do they know all this stuff? Are they taught in some sort of Russian “finishing” school?

I can understand why they can get involved in these types of organised crime schemes in the former USSR, but how the heck do they manage to do it on a global scale?