To gain an edge, this is what you need to know today. Revised CPIPlease click here for an enlarged version of the chart of SPDR S&P 500 ETF Trust (ARCA:SPY) which represents the benchmark stock market index S&P 500 (SPX). Note the following: The chart shows the revised CPI data brought in buyers to the stock market.The chart shows that volume continues to be low. This indicates that so far there is lack of conviction in the move. However, this can change very quickly. The stock market has been eagerly waiting for CPI revisions as there have been times in the past when such revisions caused majo…