The speed with which capital is shifting to the exporters of low cost goods and oil is leaving the asset management industry, including private equity and hedge funds, wondering where its next new client is coming from. Who would have expected a central bank to invest in a private equity fund, as the People's Bank of China has just done with US buyout firm TPG?

The People's Bank of China is not a sovereign wealth fund, according to asset managers, investment bankers and a US research organisation called the Sovereign Wealth Fund Institute - it is a central bank, set up to manage China's currency.