The shares of more than three quarters of FTSE 350 firms have outperformed Nvidia so far this year after the world’s biggest semiconductor firm was blighted by concerns over bloated AI valuations and its billionaire founder was caught in a relationship scandal involving an alleged spy.

Some 68 constituents of the FTSE 100 and 202 members of the FTSE 250 had eclipsed the year-to-date share performance of Nvidia at market close on Monday, according to a analysis. London’s blue-chip index is up 9.3 per cent since the start of the year, on an equal-weight basis.

Nvidia shares, on the other hand, have shed more than seven per cent of their value since the start of the year. That followed a sharp sell-off of the stock in New York on Monday after chief executive Jensen Huang admitted to an extramarital affair with an Nvidia customer and alleged Chinese spy, triggering an internal company investigation into the romantic relationship.

“Throughout my life, my family has given me love and support. They deserve my honesty and loyalty. Instead, I let them down and damaged the life we built together,” Huang said in a statement emailed to staff.

“I take full responsibility for what I did and the hurt I caused, and I accept the criticism that comes with it.”

The news wiped as much as $200bn (£150bn) from Nvidia’s market value in a matter of minutes. But the stock had already been under pressure in recent months over growing concern the AI investing boom was running out of steam, tumbling from a peak of around $240 at the start of October to $180 a month later.

“Higher interest rates, worries over how the artificial intelligence spending boom is to be funded and concerns about the Democrats’ plans for regulation and data centres are now being joined by the possibility of a scandal involving the CEO of one of the companies that sits at the very apex of the AI tree, Nvidia,” said AJ Bell investment director Russ Mould.

 “Bulls may be inclined to take President Trump’s lead and shrug off Jensen Huang’s personal problems, in the view the work he does to put Nvidia and the US in the lead in a technological race makes him too valuable to lose, but sceptics will look at past stock market cycles and wonder whether a potential scandal could be yet another reason for more air to leak out of what they see as an AI bubble.”

Mould told the FTSE’s performance “is not something many may have predicted at the start of the year. There has been a worldwide shift toward stodgier sectors in the second half of the year, notably healthcare and consumer staples, and away from tech, so it will be interesting to see if that trend continues, or whether much lower share prices – and thus valuations – in some instances tempt some investors to buy on the dip.”