Goldman Sachs Commodity Index

The S&P GSCI (formerly the Goldman Sachs Commodity Index) serves as a benchmark for investment in the commodity markets and as a measure of commodity performance over time. It is a tradable index that is readily available to market participants of the Chicago Mercantile Exchange. The index was originally developed in 1991, by Goldman Sachs. In 2007, ownership transferred to Standard & Poor's, who currently own and publish it. Futures of the S&P GSCI use a multiple of 250. The index contains a much higher exposure to energy than other commodity price indices such as the Dow Jones-UBS Commodity Index.

The S&P GSCI contains as many commodities as possible, with rules excluding certain commodities to maintain liquidity and investability in the underlying futures markets. The index currently comprises 24 commodities from all commodity sectors - energy products, industrial metals, agricultural products, livestock products and precious metals. The wide range of constituent commodities provides the S&P GSCI with a high level of diversification, across subsectors and within each subsector. This diversity mutes the impact of highly idiosyncratic events, which have large implications for the individual commodity markets, but are minimised when aggregated to the level of the S&P GSCI.

The diversity of the S&P GSCI's constituent commodities, along with their economic weighting allows the index to respond in a stable way to world economic growth, even as the composition of global growth changes across time. When industrialised economies dominate world growth, the metals sector of the GSCI generally responds more than the agricultural components. Conversely, when emerging markets dominate world growth, petroleum-based commodities and agricultural commodities tend to be more responsive.[1]

The S&P GSCI is a world-production weighted index that is based on the average quantity of production of each commodity in the index, over the last five years of available data. This allows the S&P GSCI to be a measure of investment performance as well as serve as an economic indicator.

Production weighting is a quintessential attribute for the index to be a measure of investment performance. This is achieved by assigning a weight to each asset based on the amount of capital dedicated to holding that asset just as market capitalisation is used to assign weights to components of equity indices. Since the appropriate weight assigned to each commodity is in proportion to the amount of that commodity flowing through the economy, the index is also an economic indicator.[2]

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