He argues that much of the apparent growth in value added has in fact been illusory, based on increased leverage, excess trading, and banks writing deep out-of-the-money options – for example, credit-default swaps (a $60 trillion market in 2007). “What all these strategies had in common,” writes Haldane, “was that they involved banks assuming risk in the hunt for yield – risk that was often disguised because it was parked in the tail of the return distribution.”