Ever since the financial crisis of 2007, there has been a prevalent belief that derivative financial products - swaps, options and the like - are a) useless and b) harmful. So, for example, in today's Guardian, Will Hutton castigates derivatives : Derivatives should rather be seen as economically purposeless constructs whose ease of manipulation in opaque markets makes the investment banks rich – while the rest of us take our chances. This is simply wrong. Derivatives, like all financial products, have real-world uses that benefit ordinary people and businesses. It is when they are MISUSED that the problems arise. And I would be the first to admit that in the last decade, misuse of derivatives has enriched a small minority beyond their wildest dreams and caused misery for millions. The latest scandal concerns a form of derivative use that is close to my heart. Retail customers - small and medium-size businesses (SMEs) - have been sold derivatives ostensibly to help them manag...