Third, we must reconceptualise the meaning of market risk. The efficient market hypothesis postulates that markets tend towards equilibrium and deviations occur in a random fashion; moreover, markets are supposed to function without any discontinuity in the sequence of prices. Under these conditions market risks can be equated with the risks affecting individual market participants. As long as they manage their risks properly, regulators ought to be happy.
But the efficient market hypothesis is unrealistic. Markets are subject to imbalances that individual participants may ignore if they think they can liquidate their positions. Regulators cannot ignore these imbalances. If too many participants are on the same side, positions cannot be liquidated without causing a discontinuity or, worse, a collapse. In that case the authorities may have to come to the rescue. That means that there is systemic risk in the market in addition to the risks most market participants perceived prior to the crisis.
The securitisation of mortgages added a new dimension of systemic risk. Financial engineers claimed they were reducing risks through geographic diversification: in fact they were increasing them by creating an agency problem. The agents were more interested in maximising fee income than in protecting the interests of bondholders. That is the verity that was ignored by regulators and market participants alike.
Soros also has an interesting position on the use of credit default swaps (CDS). The financial derivatives that contributed enormously to the velocity of the collapse in the financial markets.
Finally, I have strong views on the regulation of derivatives. The prevailing opinion is that they ought to be traded on regulated exchanges. That is not enough. The issuance and trading of derivatives ought to be as strictly regulated as stocks. Regulators ought to insist that derivatives be homogenous, standardised and transparent.