It looks like the ending diagonal (wave 5) might be forming on the SPX chart. The impulse waves 1 and 3, consisted of around 40 bars. If the 5th wave will be similar in time - it would suggest a bottom around 2100. The idea is to go long around 2100 for a possible corrective move up with a stop loss at the level of 2050. If the price goes below 2050 it would invalidate the presented count.