Central banks around the world, including China’s, have shifted decisively into investing in equities as low interest rates have hit their revenues, according to a global study of 400 public sector institutions.

“A cluster of central banking investors has become major players on world equity markets,” says a report to be published this week by the Official Monetary and Financial Institutions Forum (Omfif), a central bank research and advisory group. The trend “could potentially contribute to overheated asset prices”, it warns.

The report, seen by the Financial Times, identifies $29.1tn in market investments, including gold, held by 400 public sector institutions in 162 countries.