Should central banks try to make a profit from their intervention operations? The near-universal answer is no, but it certainly helps their own confidence if they do. By buying or selling bonds or currencies, central banks are trying to help overall macroeconomic conditions rather than to make a quick buck for the taxpayer. However, the very fact that the central bankers themselves like to harp on about the profitability (or otherwise) of intervention indicates that they get quiet satisfaction from being able to call the market right...