Recent market volatility has left many investors on edge, as U.S. stocks have experienced a rocky start in September again, a month already notorious for seasonal weakness. This has inevitably drawn comparisons to the painful lessons from "Black Monday" earlier in August. Last week, the S&P 500 and $Russell 2000 Index (.RUT.US)$ indices both faced four consecutive days of declines, with the $S&P 500 Index (.SPX.US)$ droppin...