Atlanta-based GreenHaven Commodity Services launched an ETF on Thursday tied to an old iteration of the popular CRB Commodity Index. The GreenHaven Continuous Commodity Index ETF (AMEX: GCC) is charging 0.85% in annual fees.

The ETF tracks the Continuous Commodity Total Return Index. That's an equal-weighted portfolio with 17 commodities. Those include everything from corn, wheat and soybeans to cattle and lean hogs. The benchmark also covers metals such as gold, silver and copper as well as foodstuffs including cocoa, coffee, sugar, cotton, orange juice, and crude oil, heating oil and natural gas.

"The American Stock Exchange is pleased to welcome and support GreenHaven as they enter the ETF marketplace," said Scott Ebner, senior vice president of the Amex's ETF marketplace, in a statement. "GCC reflects a growing investor interest in commodity-linked products."

The CRB was the first and is still one of the best-known commodity indexes. The fund will track the CRB Index as it existed prior to a 2005 reformulation, when the benchmark was rebranded the Reuters/Jefferies CRB Index and underwent a major design overhaul.

Prior to the overhaul, the CRB was an equally weighted index of 17 commodities. That distinguished it from competing indexes, which tend to weight components by their importance to the world economy or their liquidity on the financial markets. During the 2005 rebranding, the CRB adopted a new methodology that more closely mimics the S&P GSCI and DJ-AIG commodity indexes.

The "old CRB"—or CCI, as it's known—put a much smaller emphasis on energy and industrial metals. It also put a much larger emphasis on agricultural products than competing indexes.

Not surprisingly, this huge variability in sector exposures has led to huge differences in returns. The table below compares the returns and standard deviations of the S&P GSCI, DJ-AIG and CRB (data was not immediately available for the DBC Commodity Index).

Both the CCI's standard deviation and its annual returns in the past tended to be much lower, due in large part to its lower reliance on high-volatility (and historically high-returning) energy commodities.

The GreenHaven ETF, like all commodity ETFs, will invest its collateral cash in Treasuries. Its returns will incorporate changes in the spot prices, income (or losses) from the roll yield on the various contracts and interest income from the collateral Treasuries cash.

"Increasingly, many investors have concluded that commodities are an asset class that should be represented in a balanced portfolio," said Ashmead Pringle, president of GreenHaven Commodity Services. "GCC can provide investors, both large and small, with broad commodity exposure in an efficient and low-cost way. The Continuous Commodity Index by Reuters has long been a benchmark of overall commodity prices."