The annual reweightings of the two main commodity indexes may give a "significant" boost to nickel prices and push up hog futures, Societe Generale said in a report.

The changes taking place January 8-14 to the Standard & Poor's GSCI and Bloomberg Commodity Index will also spur price swings in sugar, cotton and coffee, SocGen said in the report. Reweightings in energy will be minimal, with all markets except crude oil seeing a reduction in weight.

Total assets invested in the S&P GSCI are estimated at $US60 billion, and in the Bloomberg gauge at $US65 billion. For nickel, the 22.1 per cent of daily volume being bought over each of the five days during the reshuffle represents an 18.5 per cent increase in total open interest, according to SocGen.

"The impact on nickel is likely to be the most significant across the commodity complex and the upward impact on prices could be significant," according to the report. "The reweighting in the livestock markets will likely put some upward pressure on the sector, with lean hogs expected to rise the most."

Commodity prices have plunged this year amid supply gluts and ebbing demand from China, the biggest consumer of raw materials ranging from cotton to zinc. The S&P GSCI is down 18 per cent in 2015, and the Bloomberg Commodity Index has dropped 21 per cent to the lowest since 1999.

• [Editor:Sophie]