Re: Transforming the NYSE?
Making a company amazingly successful in a superhumanly short time requires that they have a product that everyone buys, over and over, as if there was no tomorrow. Similarly, changing the stock market involves changing people's buying and selling decisions. Sure, perceptions can affect this, but if no-one acts on those perceptions, nothing will happen. So I'm in favour of the mental powers approach. In general, I'd say that this might work like a spell, requiring special skills, preparation, components, etc. It strikes me as the sort of thing that could be stacked too, in the way a wizard stacks prepared spells.
So, what I am saying is that the effect you're after needs some kind of new consumer product (ubertech maybe), and mental-based powers to influence consumers and market players to both buy the product, and to buy/sell the manufacturer's stock according to your character's wishes. Hopes this helps.
PS. This strikes me as a power that might work well with the Array Limited Power Limitation, that requires a certain group of people to be in the right place(s) before the power works. I seem to remember reading this in UMA 4th ed, but I can't track it down there, or in my HERO5e references either right now.