Broader commodity prices were up, and investors were probably bargain hunting after last week's declines, said Keith B. Hembre, the chief economist and chief investment strategist at Nuveen Asset Management.
Complications also arise when aggregating from the fine level of detail in tariff schedules up to the broader commodity aggregates that allow an overall evaluation and comparison with protection regimes in other countries.
Despite a broad commodities sell-off yesterday, a Commodity Research Bureau index remains almost 40percentt higher than a year earlier.
The company's chief executive, Ivan Glasenberg, attributed the stock slump to a weakness in broad commodities prices.
"You might overweight silver if you have a view on it, but you can't use it to replace having an exposure to broad commodities".
Two ETNs, the iPath GSCI Total Return Index and the iPath Dow Jones-AIG Commodity Index Total Return, offer exposure to broad commodities benchmarks.
Crude hit $73 a barrel in June, part of a broad commodities rally that ran alongside the stock market's second-quarter advance, after hitting a low of $33 a barrel in December.
Some, like the iPath Dow Jones-UBS Commodity Index Total Return ETN, offer broad commodity exposure.
One broad commodity index he points to as a possible candidate is PowerShares DB Agriculture.
The empirical evidence suggests that a U.S. monetary contraction leads to an immediate rise in the broad commodity price index, which possibly reflects an aggregation bias, greater expected inflation and speculation, high production costs or some overshooting due to overreactions.
This range is thus an index of the similarity in global intensity within the broad commodity category.
