Failure

Technical failure on a number of levels, making the current action look rather bearish moving forward.

Strong support on the 2000 rising Gann line.
If this fails then a re-test of the september / august lows seems very likely.

Chart of S&P500 for 21 December 2015

Cover at 2045

With the last drop into the close, a cover signal triggers, and short signal flashing.
Also failure of the 200 again.

With a 30 point decline into the close, it would be pragmatic not to go short but to wait for a bounce and see today.

Arms at 3+ also suggests a selling climax.

Chart of S&P500 for 18 December 2015