The major commodity indexes are at or near their lowest levels in more than two decades.
Nevertheless, the price of cars, which reflect nearly the entire commodity index, has been weak.
By contrast, at the August low in commodity indexes, oil prices were rising.
Funds that invest in commodity indexes don't have much of a track record.
If that were the case, then there would be downward pressure on broad commodity indexes at the end of next year.
The index of 17 commodities rose 3.09 points, to 258.91 - its largest one-day gain in more than a year.
The commodity index, rising more than 1 percent yesterday, climbed almost 4 percent for the week.
Bond prices did receive some support from sharp declines in several commodity indexes.
Copper prices tumbled, and an important commodity index fell for the first time in five trading sessions.
With the commodity index down 17.5 percent this year, corporate earnings could be vulnerable next year.