Real Madrid star Cristiano Ronaldo has already earned Juventus a fortune.

Ronaldo is expected to join Juve in the coming days for a fee of €100m.

Juventus shares have surged 22 per cent in three days, meaning the club capital has gone from €665m to €825m, report Calcio e Finanza.

Meanwhile, it's suggested Ronaldo will become the face of Ferrari when he signs for Juve.

Their holding company Exor controls, among others, Ferrari, FIAT and Jeep.