So it’s not just investors who are guilty of moving in a herd-like fashion.

Financial journalists use the same verbs and nouns with greater frequency as stock markets overheat but display more variety in their phraseology after the bubble bursts, a study by Irish computer scientists has shown.

Trawling through nearly 18,000 on-line news articles that mention the Dow Jones, FTSE and Nikkei stock indices between 2006 and 2010, Aaron Gerow of Trinity College Dublin and Mark Keane of University College Dublin found that the language used by the writers had become more similar in the run-up to the global financial crisis.

“Meaningful regularities” in language employed before the crash showed “progressively greater agreement” in “positive perceptions of the market”.

Financial commentaries from The Financial Times, the New York Times and the BBC as well as news wire services such as Reuters, for instance, deployed increasingly similar noun-phrases as the market overheated, possibly reflecting a “narrowing of reporting to a relatively smaller number of key events/companies.”