The last chart is of SPDR S&P Retail ETF ( XRT) over S&P Equal Weight ETF ( RSP). This pair has shown considerable strength in 2013, but looks to be at a point of resistance. April retail sales release Monday, and should give this pair's direction more clarity. The report will also tell a lot about the strength of the underlying economy. The economy is driven by the consumer, as consumer spending accounts for around 70% of U.S. GDP. The equity markets have seen a huge run up lately, and if retail sales show that consumer spending is strengthening, then this could be a catalyst for further US equity strength.