The S&P 500's big breakout higher today has pushed the index up to more than two standard deviations above its 50-day moving average. So while we may be establishing a new leg higher here, we're not likely to get too much more extended in the very near term. (The red zone in the chart below represents between one and two standard deviations above the S&P 500's 50-DMA.)
Heading into today, seven of the ten major S&P 500 sectors were in overbought territory, but after this morning's move, all ten are overbought. Technology is seeing a nice breakout above its 2013 range, but it still has a ways to go to get above its September 2012 high. Industrials and Financials are breaking out, though, while Energy and Materials are getting close. The fact that the cyclicals have bounced back siginficantly this week is a good sign for the bulls.