This film is about how hedge funds were ripping off the system by manipulating markets in precisely the same kinds of ways as the 'pools' of 1929. Free markets are in fact rigged by brokers, banks, & CEOs. And governments collude with them by removing legal impediments. This same behaviour caused the last Great Depression.
"This trading is the matrix for a future crisis" (remember this was said in 2007!)
In the USA "markets are not free, they are not fair".
Al Jazeera once again more insightful than Western media.