By JASON ZWEIG, WSJ, Why Your Stock Portfolio Is Acting Like a Commodity Basket
Like Tony Curtis and Sidney Poitier in the classic movie "The Defiant Ones," stocks and commodities seem chained to each other against their will, desperate to break apart but unable to let go.
In the past few years, many investors have concluded that commodities like oil, corn and gold offer independent returns that can diversify away the risks of stocks. But the correlations between stocks and commodities—the extent to which their prices move together—are in many cases the highest they have been in nearly 30 years.
This year, about 40% of the weekly movements in the S&P 500 index can be explained by weekly fluctuations in energy prices, says Michele Gambera, head of quantitative analysis at UBS Global Asset Management. That is twice the level of similarity over the past five years and roughly 20 times the level of the past two decades.
Some of the linkages between stocks and commodities are looking bizarre. This Thursday, the monthly correlation between sugar futures and the S&P 500 hit 67%, more than 10 times its level just six days earlier, says Howard Simons, strategist at Bianco Research. That is the third time this year that the linkage between sugar and stock prices surged above 60%—much higher than their long-term average of under 20%.
More here: The Intelligent Investor: Why Your Stocks Are Acting Like Commodities – WSJ.com.
