Juventus shares were down 17.7 percent at 1.39 euros at 0730 GMT after plunging almost 21 percent when trading in Milan began. Despite his years, he's become one of the best centre-backs in the world as Ajax have impressed against Bayern Munich, Real Madrid and Juventus in the Champions League.
Allegri, however, said that Juventus were "absolutely not" over-dependent on Ronaldo.
And the 19-year-old, who was not born when Ajax last reached the last four, was left stunned by what he and his team-mates had achieved.
The entire Ajax team starting 11 on Tuesday was assembled at a cost nearly half of that which Juventus paid out for their Portuguese star in the summer.
But after eliminating Real Madrid, champions for the previous three seasons, and now Juventus, Erik Ten Hag's exciting young side should not be underestimated.
The winners would go through to a semi-final against the winners of the all-English tie between Manchester City and Tottenham Hotspur.
"But we are never satisfied and the next game is also going to be important, we'll see what happens".
Ajax continue to defy the odds as they beat Juventus 2-1 to knock out the Italian giants out of the Champions League.
"We've scored goals at the Nou Camp before from corners and crosses. we can do it, no doubt about it".
And, despite conceding that they were coming up against a quality side, De Jong revealed the plan was always the same, adding: "Juve are very strong, very disciplined, we showed in the second half the team we could be".
Ajax have exceeded all expectations in the Champions League this season - and that's an understatement. But not all of them score match winning goals to take their teams to the semi-finals of the Champions League.
"It was a great corner kick", De Ligt said.