Oil and stock markets have moved in lockstep this year, a rare coupling that highlights fears about global economic growth. As oil prices tumbled early in 2016, global equities recorded one of their worst-ever starts for a new year. On Monday, oil and stocks were lower again. The S&P 500 index was down 0.7% in midday New York trading, and Brent crude futures, the global benchmark, were down $1.37 a barrel, or 4.3%, to $30.81. That followed a joint rebound on Friday. The correlation between daily moves in the price of Brent and the S&P 500 stock index is at levels not seen in the past 26 years. January isn’t over yet, but over the past 20 trading days—an average month—the correlation is 0.97, higher than any calendar month since 1990, according to data from both benchmarks examined by The Wall Street Journal. A correlation of 1 would mean […]