in 2007 a lot of people were writing about the possible double top forming in the SP â i discovered lately at first i thought it was only the SP that double topped but also found Dax 30 and Cac 40 also doubled topped, but not the other major world indicies i looked at if any index were to double top i'd have thought it to be those with the relatively small quantity of stocks - Dax, Cac, but not the 500 stocks in the SP index, and then there's the DJIA which also didn't double top so why in particular the SP500 ? did it have anything to do with the P/E ratio or emini trading ? why the SP500 index/stocks/companies and not the Russell 2000 ?