Cameron Crise, an analyst at Warburg Dillon Read, has tried to do this by making use of equity risk premiums.

ECONOMIST: Test-driving a new model

And the euro will recover against the dollar, argues Mr Crise, only if the gap between equity risk premiums in America and Europe is closed.

ECONOMIST: Test-driving a new model

Most commentators remain bullish on gold and silver into 2012, given a climate of negative real interest rates, high equity risk premiums and continued buying by emerging-market central banks.

WSJ: The End of the Commodities Boom?

And since the main macroeconomic factor which affects the comparative attractiveness of stocks and bonds is growth, equity risk premiums are largely a measure of how much risk investors think there is of poor economic growth in the future.

FORBES: The Stock Markets Are Forecasting Economic Stagnation, Not Recovery

Therefore, a risk to bulls is that hedged players find put premiums too expensive, and thus sharply reduce their equity accumulation due to the expensive portfolio insurance.

FORBES: Short-Sellers Could Take Market Lower In The Near Term