[NhanH]

If the financial job in question is an exact zero sum job (with 0 social value), then neither taxation nor charity would help at all, because essentially while doing your job you're already causing a negative value to someone else. And even if you give always ALL your wealth, you'd just return those wealth back to society. In essence, after a lot of shuffling of wealth around, you still didn't contribute anything. (And again, that's an "IF". I'm not stating whether the premise - financial job is a zero sum game - is correct or not.)

[makeset]

Doubtless there are roles within the financial industry deserving of the "vampire squid" label in social impact, but I'd expect them to be fairly obviously unethical if not outright illegal on inspection (deceptive sales of risky exotic derivatives comes to mind). Quantitative pricing of exchange-traded products (e.g. HFT) is much harder to argue against, IMO. To me it seems like a clear net positive to process information better than others to offer more competitive prices to anonymous buyers and sellers, because tightening spreads means more efficient markets through better price discovery. It doesn't sound very different than a retailer undercutting prices by running a leaner business than the competitors and afford lower profit margins. Of course the competitors are screaming bloody murder, but how is this not good for society?