Massive central bank involvement in the markets risks returning us to a de facto centrally planned economy. Those S&P 500 companies all have the same chairman; it is Ben Bernanke because his policies are affecting everybody. That is what makes money management so difficult. Correlations will ebb and flow; they always do. But what makes them go away? This will only happen when governments and central banks go away.

But if they go away, then does that not mean things get ugly? Maybe they do get ugly, but it also means that we sort out the excesses in the market. We reward the people that do the right thing and we punish the people that do the wrong thing. And we have an adjustment process that may be ugly, but then we have a period of long expansion.

Central banks are ruling markets to a degree this generation has not seen. Collectively they are printing money to a degree never seen in human history.

Eoin Treacy's view Central banks have ramped up their support for various asset markets over the last few months. As with previous rounds of quantitative easing, money creation seeps into higher yielding instruments and/or those with the potential for outsized capital appreciation. These also tend to fall quicker than might normally be expected when liquidity is removed.

The most important question right now is how likely is liquidity to be removed?

The ECB has only just embarked on its support programme for the financial sector. The fallout from a substantial haircut on Greek debt is still a major uncertainty and the need for a robust defence of the Eurozone's banks cannot be underestimated.

The Fed has committed itself to leaving interest rates on hold for an extended period and rumblings of a third round of QE are increasingly audible.

The PBoC has yet to meaningfully easy monetary and fiscal policy but as the property market decline deepens, the potential for it to follow its peers in easing aggressively is rising.

Therefore, while we can reasonably expect the eventual outcome will be at best volatile, price action continues to suggest most global stock markets are in at least a cyclical bull market. We will rely on the price action to indicate a change to this supply/demand imbalance.