Shares in cybersecurity company Darktrace crashed 30 percent Thursday after US private equity firm Thoma Bravo ended its takeover interest in the British group.
In a statement to the London Stock Exchange, Darktrace said “discussions with Thoma Bravo have terminated”.
Darktrace went on to plunge 31 percent in value to 355 pence a share.
Its share price has experienced wild swings since floating on the London stock market in April last year.
It soared by around one-fifth in August on expectation of Bravo’s takeover worth several billion pounds.
But its shares have been hit also as co-founder Mike Lynch fights extradition to the US on fraud charges.
Lynch has been accused of inflating the value of software group Autonomy prior to its sale to US tech giant Hewlett Packard for $11.1 billion in 2011.
In May, Darktrace chief strategy officer Nicole Eagan was named in a British High Court ruling against Lynch.
She had been chief marketing officer at Autonomy when Lynch sold it to HP.