Energy stocks play a diminishing role in the S&P 500 Index

Energy stocks have played a diminishing role in the S&P 500 Index for years, and a rally Monday did little to reverse the trend. The industry’s weight in the S&P 500 has plummeted as much as 73% from a record in July 2008, according to data compiled by Bloomberg. Oil and gas producers and service companies fell last month to their lowest share of the index’s value, 4.37%, since the S&P 500 Energy Index was first calculated in 1989. The group’s weight rose Monday by 0.16 percentage point, to 4.72%, as the index itself climbed 3.3%.