How much has investor sentiment and the global economic outlook shifted in the past six months?

Consider this: stocks have fallen so much during this year-old recession that 2,267 companies around the globe in the MSCI World Index have cash positions above the value of their stock and debt.

Further, that's a level of 'offering investors profits for free' that's eight times higher than the last bear market. Global companies in this category include Bank of New York Mellon (NYSE: BK), Italy's Danieli SpA, and South Korea's Namyang Dairy Products.

The U.S. and global economic slowdowns stemming from both a cyclical trough in the U.S. and the global financial crisis have wiped out more than $34 trillion in stock market value, globally. However, the mark-downs do not, in and of themselves, represent a 'buy' signal for investors, so says economist David H. Wang.

"The values are indicative of a significantly deepening recession and pervasive fear. There's fear of counterparties, fear of a lack of return on investment, fear that a home mortgage of business loan won't be repaid," Wang said. "This fear is perhaps the biggest drag on commercial activity today and until it recedes, corporate revenue and earnings will be constrained, which will make it a difficult environment for stocks."

Although world equity markets have gone from strength to strength during the past few years, globally-listed private equity shares have lagged since hitting their peak in early 2006.

Indeed, despite the fact that the benchmark MSCI World Index managed to recover and score a new high following the late-February, early-March selloff, the LPX Composite Index has not been able to keep pace. Since the March 9th low, the latter measure has underperformed the broader global equity benchmark by more than 3% and remains well shy of its old high.

While it is hard to say for sure why momentum in LPE shares has waned, the relative underperformance could be an early warning sign that institutional investors are growing wary of the risks associated with large dollops of leverage and a mad dash to cash in on the boom.

If so, that suggests now may not be the right time to be buying shares solely in anticipation that a debt-financed "greater fool" will come along and pay a higher price.

Michael Panzner is a 25-year veteran of the global stock, bond, and currency markets and the author of Financial Armageddon: Protecting Your Future from Four Impending Catastrophes and The New Laws of the Stock Market Jungle: An Insider's Guide to Successful Investing in a Changing World.