Even assuming that's true (which it's not; absolutely nothing about Wall Street is Christian), that's not what theocracy is. Again, theocracy is rule by religious authorities; even religiously motivated decisions in the US are ultimately made by lay people with little to no input from actual Christian clergy. Put another way, de facto theocracy would be a church or group of churches acting as kingmakers and consistently steering policy. That's not what's going on; Christianity in US governance, when it appears (outside of Utah where the Mormon Church does wield significant political power), is a solidly bottom-up phenomenon that doesn't go through or depend on particular religious leaders. Rule by and for Christians, assuming it's the case in the US—which again it's not; America is ruled by capital regardless of its religion—would be exactly what we'd expect since Christians make up a solid supermajority of the population of America. Calling America a theocracy would be like calling Singapore (or another competitive autocracy) a monarchy; it's wrong in both kind and degree.