The World Cup is siphoning the attention of traders, sending trading volumes down by as much as 50 percent during match times, according to a new report.

The thinner trading, meanwhile, is raising the cost of executing trades by as much as 20 percent.

“We find that [soccer] is indeed distracting, subtly impacting market depth, traded volumes and execution cost,” Citi analysts David Bieber and Kim Jensen wrote in a report released on Tuesday.

Using data from the current World Cup in Russia and the 2014 event hosted by Brazil, the analysts found what they call “football distraction dynamics” to be greater in Europe than in the US.

Indeed, in what may be the only advantage of not qualifying a US men’s team, American traders are more attuned to their trading floor than to the soccer field.

“In the US, the football distraction increases costs by only 4 percent, while in European markets it is more than 10 percent,” said the analysts, who based their study on price movements in fixed-income markets.

The Citi study is consistent with research on the 2010 World Cup by the European Central Bank, which found that the number of trades in a team’s home country fell by 45 percent during a game. And whenever the home team scored, trading activity declined another 5 percent.