For people wondering about complexity of financial products, and if individual banks and traders did or did not precisely understand the implications of what they were doing, i wholeheartedly recommend everyone read Dit kan niet waar zijn (This cannot be true) by Joris Luyendijk. He spent about a year doing “anthropology” in the London financial sector, and it's a fascinating, horrifying read. I'm not sure if that book has been translated into English yet, but otherwise his column at the Guardian makes for equally good reading [1].
1. http://www.theguardian.com/commentisfree/joris-luyendijk-ban...