#7 Renato Sanches (Jan 2016: €10 million, Now: €40 million)
Increase in value: €30 million
Having broken into the Benfica team in November 2015, Sanches quickly grabbed eyeballs with his amazing displays in the centre of the park. Breaking into the Portuguese national team by January at the age of 18, Sanches saw his market value rise to 10 million at the start of 2016.
The dreadlocked teenager really announced himself on the big stage when he put in some match winning performances for Portugal in Euro 2016 even scoring one of the goals of the tournament against Poland.
After making a big money move to Bayern Munich, the talented youngster has had a hard time breaking into the first team. With a move away from Bayern Munich already being mooted, we might well see the Portuguese star rediscover some of his swagger and confidence this season.