September holds the ignominious distinction of being the worst performing month of the year for the S&P 500 on average, going back to 1928. Not so this year. The month is also marked by a propensity for a reversal in performance, where the year’s laggards shine. While domestic stocks shook off their early September woes to turn in a strong month, that performance was underpinned by a shift in leadership. Mid and smallcap domestic stocks outperformed their larger peers while value stocks broke a losing streak against growth stocks that stretched back to the beginning of the year. Emerging market stocks were still the best performing group for the quarter, but in the final month badly lagged the developed world.