Derivative (n.) Maths used as economic warfare.
Chances are if you did not understand complex derivatives in high school maths class, you would not recognize a collateralized mortgage obligation (CMO), collateralized debt obligation (CDO), or intangible property product if it passed you in the street singing "Like a virgin". Put it like this: up until late 2007, US and European financial institutions raced to invent ever more exotic ways to package up old tired debt, fictitious patent portfolio value, and resell this to each other in sweet deals using the old technique of "if I can't understand the maths, chance are you can't either!"
The saying in Vegas is, "if you don't know who the patsy is in the game, chances are it's you". And the patsy in the derivatives scam is the middle class, through pension funds, those stores of wealth that are an irresistible target for clever and greedy people.