Historically speaking there is a saying in the equity markets of sell in May and go away, last May we saw a 7% correction from the highs and the May before that close to a 10% correction.
S&P daily
With the market focus being on the FOMC on Wednesday evening and then the non farm payroll data this Friday these could be the catalysts for some downside in risk, coupled with the geo-political events in Crimea. I think a miss this Friday would give the market reason to start selling risk, we would need some momentum to gather pace but then it could be self fulfilling.
Last Fridays lows come in at 1859 on the cash maket and below that is the 1809, a break below and I cant see much until the 1737.