The semi's are a very good indicator of economic strength. When demand is high it's a good sign of economic growth. Notice on the first chart how the semi's resisted making new lows in 03 as the market was putting in the final low before the multi year rally. Now look at the recent chart of the semi's. Does this look like strong economic times ahead to you? I think today was just an oversold rally. This is how the bear keeps everyone riding all the way down. As I've said before markets go up different than they go down. The bull does his best to buck you off and the bear (that sneaky bastard) will do anything he can to keep you on board for the full ride down. If you let emotions control your investing decisions then they will both be successful. Remember our objective is to beat the market not let the market beat the crap out of us.
I've added the chart of copper, also a good indicator of global economic strength.