Gasoline futures fell to a three-month low on Tuesday and are 2 percent lower over the past week even as crude oil futures are flat. And that could be very good news for a few specific areas of the stock market.
When Erin Gibbs of S&P Capital IQ ran a correlation analysis comparing gas prices to S&P 500 industry group performance, a few specific areas stood out as potential gainers on the gas drop.
The industry group with the biggest negative correlation to gas prices is the airlines, which is "as expected, given that on average, 30 percent of airlines' operating costs are fuel," Gibbs wrote to CNBC.
However, another group with a large negative correlation to gas prices is less obvious: food and staples retailers.
That's an industry "you might not necessarily think of" in terms of gas prices, but like the airlines, "a lot of their cost is actually about transporting all of those goods," Gibbs said. "And if gasoline prices go down, they do very well."
For instance, one of the members of the industry group is food distributor Sysco, which operates the second-largest private truck fleet in the country, according to the industry newspaper Transport Topics' 2014 rankings.
And as gas prices have fallen of late, the food and staples retailing industry group has become the best-performing one in the S&P 500, with a 5.8 percent gain in July.
On the other hand, the names that could be in trouble according to Gibbs are somewhat more obvious: the energy equipment and services industry, and the construction and engineering industry.