The philosophy that has helped me both in making money as a hedge fund manager and in spending it as a policy oriented philanthropist is not about money but about the complicated relationship between thinking and reality. The crash of 2008 has convinced me that it provides a valuable insight into the workings of the financial markets.

The efficient market hypothesis holds that financial markets tend towards equilibrium and accurately reflect all available information about the future. Deviations from equilibrium are caused by exogenous shocks and occur in a random manner. The crash of 2008 falsified this hypothesis.

I contend that financial markets always present a distorted picture of reality. Moreover, the mispricing of financial assets can affect the so-called fundamentals that the price of those assets is supposed to reflect. That is the principle of reflexivity.

Instead of a tendency towards equilibrium, financial markets have a tendency to develop bubbles. Bubbles are not irrational: it pays to join the crowd, at least for a while. So regulators cannot count on the market to correct its excesses.

The crash of 2008 was caused by the collapse of a super-bubble that has been growing since 1980. This was composed of smaller bubbles. Each time a financial crisis occurred the authorities intervened, took care of the failing institutions, and applied monetary and fiscal stimulus, inflating the super-bubble even further.

I believe that my analysis of the super-bubble offers clues to the reform that is needed. First, since markets are bubble-prone, financial authorities must accept responsibility for preventing bubbles from growing too big. Alan Greenspan and others refused to accept that. If markets cannot recognise bubbles, the former chairman of the US Federal Reserve asserted, neither can regulators – and he was right. Nevertheless authorities have to accept the assignment.

Second, to control asset bubbles it is not enough to control the money supply; you must also control credit. The best known means to do so are margin requirements and minimum capital requirements. Currently they are fixed irrespective of the market's mood because markets are not supposed to have moods. They do, and authorities need to counteract them to prevent asset bubbles growing too large. So they must vary margin and capital requirements. They must also vary the loan-to-value ratio on commercial and residential mortgages to forestall real estate bubbles.

Regulators may also have to invent new tools or revive ones that have fallen into disuse. Central banks used to instruct commercial banks to limit lending to a particular sector if they felt that it was overheating.

Another example of needing new tools involves the internet boom. Mr Greenspan recognised it when he spoke about “irrational exuberance” in 1996. He did nothing to avert it, feeling that reducing the money supply was too blunt a tool. But he could have devised more specific measures, such as asking the Securities and Exchange Commission to freeze new share issues, as the internet boom was fuelled by equity leveraging.

Third, since markets are unstable, there are systemic risks in addition to the risks affecting individual market participants. Participants may ignore these systemic risks, believing they can always sell their positions, but regulators cannot ignore them because if too many participants are on the same side, positions cannot be liquidated without causing a discontinuity or a collapse. That means the positions of all major participants, including hedge funds and sovereign wealth funds, must be monitored to detect imbalances. Certain derivatives, like credit default swaps, are prone to creating hidden imbalances so they must be regulated, restricted or forbidden.