Looking at Weekly chart of S&P500
chart it seems that Fib Expansion formed from Mar'09 low @ 680 to May'11 high @ 1372 to Oct'11 low @ 1075 is targeting 1.618 Fib Expansion @ 2080. As this is all time high and unchartered territory we might very easily see it roll over from here or even slightly higher around 2100 (nice round number). These are approximate levels and the current bull run is way overextended. I'm more of a BEAR at the current levels and a future retracement is eminent.