Manchester United top the global spending table across the past decade, spending £1.19bn more than they have recoupled through player sales.
Since 2014, the Red Devils have spent £1.67bn on new players, while receiving £481m on sales, according to the CIES Football Observatory.
Notable transfers in that time include Paul Pogba for £89.5m in 2016, Harry Maguire for £80m in 2019 and Romelu Lukaku for £75m in 2017.
All three of those players, as well as other big-money signings such as Antony and Jadon Sancho, have struggled at Old Trafford with the Red Devils having no Premier League or Champions League success to show for the past decade.