So why not bet on a possible irrationality of European decision-making? European policy makers may have underestimated the self reinforcing nature of market trends.
If a speculative strategy based on a certain hypothesis, such as the default of Greece, delivers capital gains over time – as has been the case since the fall of 2009 – it is  2  BIS Review 50/2010  bound to attract an increasing number of investors. As a result, the market pressure increases, making the hypothesis more realistic.