Given the cost of taking 4+ years of your life to train under someone learning a skill, yes, there's a huge financial risk in doing this. If you're able to ign

Given the cost of taking 4+ years of your life to train under someone learning a skill, yes, there's a huge financial risk in doing this. If you're able to ignore that fantastic, great for you and I hope you're happy, but even fully funded positions have just enough money to cover the minimum length of a PhD. To get the most from it chances are you will either end up with minor debt or wipe out some savings. Unfortunately such is life. IMO the goal of the PhD shouldn't be to think of a city job as a high frequency trader at the end, but that's my worldview that why spend X years studying in a field of you don't intend to follow it... Chances are if you say that during an interview for a place, unless it's in studying high frequency trading you won't get a call back.