Well you sound like someone who thinks the "cat's in the bag". Ever heard of Schrodinger's Cat? Your cat may be dead to begin with.

That being said, it is extremely competitive to get into QF, reason being majority of the Maths major all want to major in QF (read: PRCs). Have you taken any Math module? If so, you will understand that it's no longer about solving equations or math problem. Rather, it's about now using Math as a language of science, like understanding the principle behind why 1 + 1 = 2 and not 3,4 or 5. I hate to admit it, but for Singaporeans who went through the conventional education system, we are lagging behind those students from China in terms of exposure and experience in Math. So unless you love and breath Math, think of what will happen IF you do not get into QF. Even then, should you get into QF successfully, you will be competing with the creme de la creme. Should your honours be sucky at the end of the day, you can bet your horses no banks will want you. Afterall, NUS ain't Ivy League to begin with.

Not to splash cold water, but if you do want a career in IB, be very sure to do the correct internships, and get that FCH. FCH just gives you that opportunity to be interviewed, while internship is the one that will determine whether you are hired or not (most of the time anyway).