Factors that influence the price of commodities include global supplies, demand, macroeconomic factors, production quotas, and geopolitical tensions. For example, the Russian invasion of Ukraine caused a spike in global natural gas prices, while the US-China trade war caused cotton prices to climb higher than expected due to a strain in the supply. In addition, the Organisation of Petroleum Exporting Companies (OPEC) sets production quotas for member countries, and the US Federal Reserve, the European Central Bank, and the Bank of England use higher interest rates to curb demand. Finally, commodities offer investors the opportunity to spread their risk portfolio, and historically commodities outperform stocks and bonds in times of market volatility.