It seems to me that many of the people we see as great programmers are those who made their mark on a particular field of programming. So my answer would be, if you're already an okay programmer (can get hired at Google or a hedge fund), you could pick a subfield that intensely interests you, and just dive as deep as you can.

The reason most people don't do that is most jobs have a mismatch between what's interesting to you and what's useful to the employer. It's worth trying to minimize that mismatch and get encouragement from your employer somehow, though I have no idea how, it seems to mostly depend on luck.