Wut? SPY and SPX and DOW are the same thing? I'm now actively thinking of hitting my head on my desk... SPY is an ETF, which tracks the SP500 index SPX is the SP500 index, calculated by CBOE, also has futures traded on it (SPX futures which are SP500 full) ES is the SP500 index, calculated by GLOBEX, also has futures traded on it (ES futures, which are SP500 mini's) DOW is a different index... the Dow Jones Industrial Index. Futures on it are YM, which are minis. The only ones that move in sync are ES and SPX, the futures on both track each other very closely. SPY is an ETF... which is traded differently, should track the SP500 stocks in the same configuration as the index. Big difference is dividend payouts, which are at different times than the actual stocks in the index. - Index levels are total of all components in that index, based on their correct weighting. - Futures trade roughly at levels of the Index + Interest -/- expected dividends up until the expiry of the futures. - SPY... just tracks the index closely and pays out dividend quarterly I think. There's probably some adjustment factor as well, depending on whatever it depends on... read the prospectus.