Juventus' shares fell by nearly 22% on Wednesday after being knocked out of the Champions League by Ajax.
The shares recovered slightly on the Milan stock market but were still down by 17% during the early trading.
Matthijs de Ligt scored with just over 20 minutes to go as the Dutch side came from 1-0 behind to win 2-1 at the Allianz Stadium - which meant they won the quarter-final tie 3-2 on aggregate.
This will not be good news for the Agnelli family, who are the founders of motor company Fiat and have been running the Serie A side since 1923.
Ajax's shares were up by 7.58% after their victory and this has now valued the club at £272million.
Cristiano Ronaldo had given his side the lead in the 28th minute when he was unmarked from a corner.
Then five minutes later Erik ten Hag's side were level as Hakim Ziyech's shot deflected into the path of Donny van de Beek who put the ball home.
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The Dutch side will play the winner of Manchester City and Tottenham's quarter-final who play their second leg on Wednesday night.
Barcelona knocked out Manchester United on Tuesday to book their semi-final place and will play either Liverpool or Porto in the next round.
Source: dailymail