Those resources stocks were starting to look stretched after a really good year last year, so all it takes is a drop in commodities across the board for them to come off. Some stocks will benefit, though, particularly the manufacturers as their costs go down.

The question is how far does it go from here. Certainly the environment is conducive to strength, because the global economic fundamentals are good.

There is still some volatility in global metal prices which is a cause of worry for the resource sector.