Shares in the dating business Match Group, which owns the dating app Tinder, fell after Facebook announced that it would be rolling out its own dating service.
Match Group closed more than 22 per cent below their opening price on Tuesday, after Facebook founder Mark Zuckerberg took the opportunity to unveil a dating service at his firm's annual F8 developers’ conference in California.
He told his audience that the match-making feature would take privacy issues in mind and would launch "soon".
"There are 200 million people on Facebook who list themselves as single," said Mr Zuckerberg.
"And if we are committed to building meaningful relationships, then this is perhaps the most meaningful of all."
He said the opt-in feature would focus on "real long-term relationships, not just hook-ups", and would exclude existing friends from potential matches.
"We have designed this with privacy and safety in mind from the beginning," he added.
It pays Facebook to be conscious of privacy and safety – the company has been fiercely criticised for failing to check whether political consultancy Cambridge Analytica had deleted data harvested about millions of its users.