The element that had been more unexpected in the current crisis is the rigour with which systemic risk has been triggered by the collective behaviour of financial institutions and the  2  BIS Review 166/2009  ways in which they interact in financial markets.
The crisis has highlighted the importance of improving our understanding of interconnectedness in the financial system, both via the direct links between financial institutions and the indirect ones created in financial markets. The crisis has taught us that major risks can emerge from within the financial system itself. It was not the real economy that threw the financial system into disarray, but the reverse.