Technically, the fact that both the Dow Jones Industrial Average and the S&P 500 Index closed below their respective 200-day moving average (DMA) lines suggests the market may retest its recent lows. Looking forward, the 50 DMA line should now act as resistance and this month’s lows should act as support. Since the June 15, 2010 follow-through day (FTD), this column has steadily noted the importance of remaining very selective and disciplined because all of the major averages are still trading below their downward sloping 50-day moving average (DMA) lines. This week’s sell off simply confirms that view. Trade accordingly