Corporate Bond Yields: the Best Indicator?

I was watching CNBC today, and one manager made perfect sense. He said stocks were low based on valuation, but he was in cash. He indicated he was going to wait until the market stabilized before investing in stocks, because right now, the market was behaving irrationally, and he did not want to risk timing a recovery too early. He also said that when yields on safer (GE, etc.) corporate bonds narrowed, that might be the time to buy stocks. He was long cash and corporate bonds. If you want to follow his advice, you may want to consider buying iShares S&P U.S. Preferred Stock Index (PFF), a preferred shares ETF, and/or T. Rowe Price's Corporate Income Fund. I own PFF, and may buy some of the T. Rowe Corporate Income fund.