Awaiting Confirmation of SDS Bottom

The e-mini S&P 500 is approaching key support at 1171.00, and the S&P 500 Depository Receipts (SPY) is approaching key support at 118.00-117.60.  So why aren't I positioning myself long the UltraShort SPY (SDS)?

The developing pattern in the SDS is starting to take the shape of a 4-week base-like formation that could propel prices considerably higher -- if the SDS can hurdle and sustain above key resistance between 27.66 and 27.91. Such a move will trigger upside targets of 28.50, and then 29.50.

That said, the underlying SPY must break and sustain beneath key support at 118.00-117.60 to trigger a significant sell signal that corresponds to an upside breakout in the SDS. Otherwise, all of the action off of the 11/05-11/09 lows at 25.39/35 represents a countertrend move within the dominant (down) trend, which when complete will resolve in a downside continuation into new low territory.