This is due to the fact that it has generally been uncorrelated to other asset classes while healthy growth in China and other developing economies, is expected to keep prices strong. In short, it would appear that commodities have become a much more sought after “new” asset class for many portfolio managers.
BIS central bankers’ speeches  3  The Bank’s analysis indicates that the real exchange rate is well above its sustainable level and also above levels justified by short term business cycle factors. Other institutions also consider New Zealand’s real exchange rate to be unsustainable.