A significant relative strength event happened yesterday when the iShares S&P 100 Index ETF (OEF) climbed up into the Green Favored Zone of the SIA S&P 100 Index Report by moving up two spots to 26th place. This is the highest rank the Index ETF has achieved, topping previous peaks at 27, the top of the yellow zone. OEX reaching the Green Favored Zone means that 75% of the stocks in the SIA S&P 100 Index Report are losing in head to head battles with the Index.