it probably is a low risk trade,as you are at a major resistance point on the s&p 500.it will be even more reliable if you confirm it with a reversal pattern.
this is well presented in holygrail" s synopsis
you could use other confirming signals on a candle chart..such as oscillator divergence and or looking at dmi/wait for the range to get smaller ie the directional movement must be getting smaller.there should be a reasonably definite area of support/res that keeps the price in check
hope this helps
please do youre own analysis.this is my opinion only