(Adds economic reports from today showing few signs of improvement.)BOSTON ( TheStreet) -- October has a history of being an especially cruel month for investors. And if the stock market's disastrous performance and volatility in the third quarter was a prelude, it may well be again. Economists are divided on whether the U.S. economy is about to fall into a recession and drag the equity market and Americans' 401(k)'s down with it. That's a scary prospect because the benchmark S&P 500 Index is nearing a bear market, having declined almost 20% since late April. Other asset classes such as commodities, oil and real estate also have fallen.