Today's breakdown and close below the July high of 46.15 in the Qs on volume greater than the 8/6/08 breakout is a sell signal on the Weekly - Daily price system. We never had a valid buy signal on the breakout due to the weak volume and now the Monthly downtrend has been reconfirmed. There is still a chance that a reversal from today's level back above 46.15 could "save" the markets, but it doesn't look like that will be the case. The Cabot's Tides also gave a sell (short) signal today.
In prior posts I indicated that we should expect a reversal no later than September 9. Today's breakdown probably indicates that the rally will not make it to that date. The fact that the 22 week cycle low came late (July 15 vs June 24) and the current 22 week cycle high is coming early portends significant weakness this fall.
Expect a test of 46 from below in the near term followed by an accelerating downtrend. If the current trend does accelerate, it would probably be unprofitable to try and trade the bounces as downside gaps may be common. This is a trend to hold onto once your in the trade.
If you get stopped out, don't be afraid to give a couple of more chances. It could be very rewarding on the short side.