Look up Spiv on t'internetz. Google it. It will tell all.
Then I'll tell you what one is, and why Vince doesn't want one.
A Spiv is not someone who doesn't work. A spiv is someone who works bloody hard, actually. DelBoy Trotter would be a Spiv. Private Walker in "Dad's Army" was one.
What they do is to see market opportunities that for some reason or another other people fail to exploit. That may be because they're seen to be immoral (such as selling Jew's teeth), because they're illegal (such as selling cannabis), because they're not available (such as selling parachute silk in the war) or simply because you didn't think of it first.
Vince describes bankers as Spivs. Maybe so. But they're not. The reason is that the common factor with all Spivs is that they don't "engage with society", which is a polite way of saying that they may deal mainly in cash and therefore may not declare everything that changes hands to Messrs Revenue and Customs.
And why, the fuck, should they, I ask in all seriousness?
If I have a job, and I earn a pound, the government gets some. They may get as much as 50p. I then have a window cleaner, because I don't like heights. And he charges me money. If he charges me a pound, I have to pay him two of the pounds I earned, leaving me fuckall, and the government gets another (as much as) 50p. The window cleaner now has 50p, I have the square root of jack shit, and the government has £1.50. Explain why that's right. Go on.
So, ladies and gentlemen, become a Spiv. You know it makes sense.
NOW do you see why Vince doesn't like them? Because the don't pay his wages.