Politicians need to see there’s something worth boosting. The current hollowing-out is not healthy

Another day, another takeover bid for a UK-listed company. In fact, Thursday saw three in one gulp. Bath-based Rotork, which makes safety valves for pipelines, is falling to Swiss group ABB for £4.1bn. Gooch & Housego, a specialist in precision optics for aerospace and defence, is being bought by a US investment firm for £346m. And Ramsdens, a financial services and pawnbroker firm, is also being taken over from the US for £230m.

Individually, the deals represent splendid one-day news for the firms’ shareholders since the premiums on the pre-action share prices are 73%, 41% and 49%. Collectively, however, they are yet another depressing chapter in the tale of London’s incredible shrinking stock market.