The Arm Holdings flotation in New York is so important for confidence in the comatose IPO market globally that there will be much relief in London that it has been a success.

But there will also have been some in the City who were secretly hoping it would somehow go wrong. After all, the decision by Arm’s owner SoftBank to choose New York for the IPO has become a symbol of what is widely seen as a critical decline in London’s attractiveness.