Update with an IWM weekly chart. IWM 7 EMA has broken down 21 EMA a while. In contrast, SPY just touches 21 EMA. If market is considered being bottomed, at least , 7 EMA should touch 50 EMA. Conclusion: SPY could move down to 129.4 (50 EMA). And seems at end of its up-trend.
By this week, 7 EMA (weekly) has broken up 21 EMA (weekly). read blue-mark in the chart. In my ST system, it signals bullish market. Those red-marks are sell-points. In an average correction, 7 EMA hits 50 EMA. But in a deep correction, such as August 8th 2011, 7 EMA could run down below 50 EMA.