Don't be fooled by the parade of talking heads on CNBC proclaiming that this is the buying opportunity of a lifetime, says John Hussman, President of Hussman Investment Trust. "Investors shouldn't kid themselves that stocks are cheap – in the sense of being priced to deliver outstanding long-term returns – just because we've observed a wicked decline," he writes.

Hussman explains that the current price-to-book ratio on the S&P 500 is about 1.9, which is still much higher than the ratio's historic lows. This means that stocks are still trading at a slight premium - hardly the bargain that everyone is talking about.

"If you think about the 1974 and 1982 lows, we observed price-to-book ratios at about 0.8," he explains. "So the S&P 500 would have to drop by about 60% to match the best valuations that we've seen during the past 40 years."

And finally, it would seem wealthy investors agree with Hussman's assessment. A Barclays Capital survey of 2100 people with more than $820K in investable assets found that the majority (68%) of respondents are still afraid to take risk.