I hope you have decent source of secondary income or your family is reasonably well off.
A math PhD might take 6-7 years to complete and I hope that, at the end of it all, you won’t have to come to London to look for C++ or Ocaml jobs at hedge funds or banks.
Because i have worked with many math phds who lost their youth to something that they could not make a living on (research positions at universities are few and the competition is intense) and were writing C++ implementations of derivatives pricing models for a (comfortable) living.
I am not trying to discourage you, just a different perspective.
Well, luckily I'm not doing this in the hope of increasing my earning potential. It's an entirely separate pursuit. I have no doubt that what you're saying is true, but I don't think I'm bothered by it since it's not my goal.
A math PhD might take 6-7 years to complete and I hope that, at the end of it all, you won’t have to come to London to look for C++ or Ocaml jobs at hedge funds or banks.