Paul is traveling currently, so let me respond - sorry for the delay.
I think you have two primary issues in play, which is true for most people:
1. Your GPA. You know this already, so it's nothing new, but it's important that you understand that your GPA is not just a bit low, it's very low. 2.9-3.3 is a pretty manageable place to be in a b-school process because most MBA programs understand that college was a lifetime ago and there's all this water under the bridge since then. However, 2.6 range is a tougher pill to swallow. Not only do they have to put that on their ledger (hammering their average), but it speaks to more than just a few late nights freshman year. The onus will be on you to really showcase a high level of maturity, focus, and discipline. More than coursework, they want to know that the lightbulb came on.
2. Your path. The idea of college behind a lifetime ago and the lightbulb coming on leads me to my second concern, which is that your path is going to seem disjointed or even downward. Now, whether this is true or not is irrelevant. It might even be unfair for someone to perceive it that way. But if you started in equities trading and you want to get back into finance ... why are you out in the wilderness (so to speak) right now? The mind is going to assume that something went awry. So not only do you have a rocky college experience in play, but perhaps you haven't been a dominating, ambitious, focused machine since then. Again, I'm not saying this is true at all, I'm saying how a reader might build a narrative around your data. So what this means is that in addition to showing maturity, focus, and discipline, you have to show that your years since college are propulsive, positive, and transformational. You'll have to sell each and every step you've taken as being this amazing process of acquiring skills and perspectives that have you completely prepared for an MBA, for your immediate job afterward, and for your long-term pursuits.
You can do it at schools in that 15-40 range, I think, but it will be a bit of walking the tightrope because you don't have much (well, any, really) margin for error.
I hope this has been helpful and not discouraging.
Best,
-Adam/
Amerasia