The Express and Star first revealed that Boly was going to join the club on a permanent deal for £10 million.
He had spent the past season on loan at Wolves, impressing in most of his appearances.
Now the club is set to activate the buy clause within the loan agreement, per O Jogo in Portugal.
Porto director of communications Francisco Marques is the one who says the buy clause has been activated.
He spoke with O Jogo about the club's transfer budget, during which he said: "And 12 million (Euros) from Boly, because Wolverhampton have already activated the option..."
Wolves also confirmed they have "triggered options on in the loan agreements" for Boly and striker Benik Afobe.