Hey Mike,
If you have impressive work experiences in IBs, HFs, or the financial/banking industry, I say that will greatly offset any weaknesses in your application. I spoke to many Professors on the admissions committee from some of the top programs; since the quality of a program is primary or
is judged by its placement records, the admissions committee quite often will overlook your mathematical background in favor of your demonstrated "employability".
Please note, however, that the more prepared you are, mathematically and computationally, the more you can benefit, absorb, and learn, intellectually, from one of these programs. Consider a seasoned manager versus a student straight out of college in an MBA program, it's obvious who is capable of benefiting, absorbing, and learning more through the program. You can check out students from some of these top programs (
http://www.baruch.cuny.edu/math/Students2006.html) and you will see how fundamentally sound and well-prepared some of these students are. Mike, if one is encountering the presumably advanced topics in mathematics or deriving the Black-Scholes formula for the first time in the program, the truth is that he or she is already behind and the nontrivial consequence is that the intellectual benefit that one can get out or derive from one of these programs is then limited. The principles of leverage apply aptly well in this situation: the more you know, the more you'll be able to learn, experience, and enjoy this world. You have the inherent advantage and check mark next to "employability" so my advice to you is to enter a program as prepared as you can so that you will be able to hit the ground running once the program commences.
At the end of the day, you have to ask yourself what you want to accomplish in one of these programs and why you want a degree from one of these programs. (Incidentally, I believe these are the personal statement/essay topics of many programs
). If your goal is to switch roles within your current institution, I wouldn't stress out over your background with regards to the application itself. If you are genuinely interested in improving mathematically, many of the forum participants will gladly guide you to the relevant mathematical subjects in this field/profession.
I'm constantly distressed by applicants asking the wrong questions. (e.g. Is this "enough"? What's the "minimum"? And questions about the venerable three letter word organization I will refrain myself from mentioning. No, it's not the SEC or FBI!) I hope you will find my post helpful.
Good luck!