Short answer: Al-Hilal have the biggest net transfer spend in football over 2022–2026, at -€873.3 million, according to CIES: €925.1 million spent and about €51.8 million recouped. Tottenham Hotspur (-€840.4M) and Manchester United (-€830.8M) are second and third, and Chelsea are fourth at -€762.3 million....