This is what a pimple on the ass of common sense looks like.
The crash was caused by derivatives? Please explain further.
Derivatives are more or less bundles of loans made by different banks. They would bundle say 100 mortgages together, and then look for investors to 'buy the debt'. It was a way to trade in debt, brokers made huge profits taking debt that banks owned and selling it to A) Ignorant people who believed ratings given by people who profit more the more that is sold B) The taxpayer through fanny and fredie thanks to a 100% corrupt government
So you have more and more derivatives cause a bank can write loans risk free by just bundling the loan into a derivative and then having gulibul people with savings buy the snake oil. Were talking about people activly buying and selling debt and trading in it, much the same manner as enron trading in energy futures. Making money hand over fist while contributing nothing to the market except enabling it to inflate. Drives up the prices of anything banks lend for because agian they were loaning reletively risk free.
The dirivative market has partially fallen already, thats what the bank bailouts were for, they needed money so they could 'clear the debt' without going bellyup, which would have cause all investors to belly up and so on and so forth. But the bottom line is the debt is not cleared, it is still sitting on an institutions books be the government banks or insurance company's, or the peoples retirements.
Thats what people are pissed about, is that there has been no justice for this crime. The purpatrators did not even have the free market punishment of bankruptcy to deal with, they manipulated the government to dump it on the taxpayer.
So to put it all in one sentence a derivative is a vehicle that banks use to make huge profits giving out loans, keeping the profit, and dumping the risk on the taxpayer and the public.