The measures how fast the market is moving in a particular direction over a period of time. The 52-week ROC is often used to monitor long term trends. The 52-week ROC crossed the zero line twice since 2007. Dec 2007 (end of the run started in 2003 ) and Oct 2009 the beginning of the new market. The market could be close to an end. Another cross of the ROC 0 line would be the confirmation.