Unless the recent market action is a mere 2 or 3 month discontinuity, the August close below the monthly MA 9 (now at SPX 1950) signals a change of trend.
This system generates huge profits. But sometimes it's quite tricky. In the years 1998, 2010 and 2011 the system gave false signals. Traders/Investors who went back in as soon as the monthly close was back above the MA were on the right side of the trade, didn't lose too much. Nor did those who went long at the false buy signal in 2002 if they sold in March.
Whoever used this system as from December 2011 is a rich man now