And then, in just two days last week, the exchange traded note ( ETN ) that tracks it sank more than 20%. Speculation that China would increase interest rates to cool inflation in its economy sent fear through the market that the world's largest commodity consumer would be stepping back, says Debarati Roy for Bloomberg . Both international and domestic sugar prices have hit 30-year highs in 2010 and pushed iPath Dow Jones UBSSugar TR sub-Index (NYSEArca: SGG) up more than 92% in the last six months.