Transfermarkt updated their market values on December 30, and Vinicius Junior's went from €50m to €100m.
The Real Madrid winger is currently the world's third-most-expensive player, only behind Kylian Mbappe (€160m) and Erling Haaland (€150m).
He shares the third spot with Mohamed Salah, Harry Kane and Romelu Lukaku.
It should also be mentioned that Vinicius is currently the most expensive player in La Liga and at the club.
The 21-year-old has gotten his market value boost thanks to his impressive performances for Real Madrid this season. This term so far, Vini Jr has recorded 12 goals and nine assists in 25 games.