Wolves have signed winger Helder Costa on a more permanent deal, until 2021, for a club record fee of £13m.
Portuguese Costa, 23, who initially joined Wolves on a season-long loan from Benfica in July, has impressed in his 29 appearances for the club.
The Championship club's previous transfer record was Portuguese forward Ivan Cavaleiro, who joined from Monaco in a reported £7m deal in August.
Wolves are 18th in the Championship, seven points above the relegation zone.
But despite their inconsistent league form, Paul Lambert's side have reached the fifth round of the FA Cup, twice beating Premier League sides, first Stoke City, then 2-1 last Saturday at Liverpool.
Costa becomes the fifth player to move to an English Football League club this season for a fee of more than £10m, following Newcastle United pair Dwight Gayle and Matt Ritchie, then Ross McCormack's transfer to Aston Villa, who also signed Bristol City striker Jonathan Kodjia.
Kodjia is believed to be the most expensive signing in Championship history, having signed for an initial £11m, with add-ons taking his cost to £15m.