Commodity performance in September was generally driven by global supply surpluses across multiple commodity sectors, according to Credit Suisse Asset Management.

The Bloomberg Commodity Index Total Return performance was negative for the month, with 18 out of 22 Index constituents trading lower.

Credit Suisse Asset Management observed the following: 

• Agriculture was the worst performing sector, down 9.54%, led lower by grains, as exceptional growing and harvesting weather has helped support a record crop year. 
• Precious Metals decreased 7.55%. Gold and Silver declined as the US dollar continued to strengthen. US monetary policy now seems to be on a tightening course, while other major central banks continue to ease. 
• Industrial Metals declined 6.65%, with all constituents posting negative returns due to weaker than expected Chinese economic data. Chinese officials continued to indicate the government would not be increasing stimulus measures to offset recent economic weakness, potentially decreasing the demand for base metals. 
• Energy ended the month 4.41% lower, led by Brent Crude Oil, after the International Energy Agency and OPEC both forecasted a weaker outlook for crude oil. OPEC increased its production forecast for non-OPEC producers, while the IEA cut its demand forecast. 
• Livestock was the best performing sector for the period, up 5.74%, as production of beef and pork remained low. 

Nelson Louie, Global Head of Commodities for Credit Suisse Asset Management said: "September was generally driven by global supply surpluses across multiple commodity sectors. While record levels of production for grain-related commodities led to lower prices for the 2014 crop year, global consumption continues to trend higher. With base level global consumption at much higher levels, any disruptions in future crop years may materially impact prices. Despite expected increases in US shale oil and gas production, natural gas and heating oil inventories are still at multi-year lows, making supplies more susceptible to extreme weather conditions. There were also some early signs of the persistent South American dry weather potentially beginning to impact next year's crops."

Christopher Burton, Senior Portfolio Manager for the Credit Suisse Total Commodity Return Strategy, added, "Global growth will be a key factor for commodity demand expectations improving over the long-term. Economic conditions in the US continued to improve, including unemployment. Meanwhile, the European and Japanese central banks continue to add stimulus in an attempt to jump-start their economies. The corresponding strengthening of the US dollar as a result of the divergent paths in central bank policies has undoubtedly weighed on commodities as of late, but this may be a short-term drag.  In the medium- to long-term, rising rates and a strengthening US dollar may coincide with improving economic growth.  Macroeconomic factors may reinforce themselves, via the sources of inflation or growth surprises, both of which may come in above low expectations."