Darktrace tumbled on Wednesday after private equity firm Vitruvian Partners sold 11m shares in the cybersecurity group in a placing.
The shares were sold at 580p each, raising gross proceeds of around £63.8m.
Following completion of the placing, Vitruvian will hold just over 20.8m ordinary shares in aggregate, which is a stake of around 2.99%.
Berenberg and Morgan Stanley acted as joint global co-ordinators and joint bookrunners.
At 0805 GMT, the shares were down 7.7% at 584.00p.
