Carney warns market performance may not be justified

He added there must be some doubt as to whether more of the measures used by central banks since the financial crisis, such as cutting interest rates or instigating the bond buying programme known as quantitative easing, will be effective, given how low interest rates already are.

Lower interest rates typically boost share prices in the short-term, because they push down the returns available on safe haven assets such as government bonds and cash, making the returns available from equities relatively more attractive.