You're a director in an investment bank. In your fantasy, you will one day be a managing director (MD) in that investment bank. Except that it's a lot harder to make managing director than it used to be. You may therefore be tempted to quit and do something completely different. Don't - for as long as becoming an MD looks like a possibility, it's worth persisting with. Because managing directors make A LOT more money than directors.
Witness the chart below, from Emolument.com, the real time salary data specialist. The pay rise between director and managing is the steepest of the lot. Male directors in front office roles earn an average of £222k ($348k). By comparison, male managing directors earn an average of £421k. For females, the figures are (depressingly) £186k and £317k respectively.
Of course, money isn't the only reason to work somewhere. If you've spent years toiling in the middle tier of an investment bank and are despairing of the role, your lifestyle, and ever getting promoted, quitting is no bad thing. But it's good to know what you're walking away from.