Paul Gambles, Managing Director of MBMG Group, said following the 2008 financial crisis, global central banks pumped trillions of dollars into the economy to boost lending and encourage growth.
This has led to a significant increase in stock prices, taking global stock markets to the brink of bursting.
Mr Gambles said: “We had a policy response to the global financial crisis (and) at that point stocks were cheap and they had an enormous tailwind behind them in terms of fiscal support.
“This is quite a dangerous situation and it is creating a bubble, and that bubble has just got bigger and bigger and bigger
“There isn’t any doubt now (that) in valuation terms we’re in epic bubble proportions, probably the biggest bubble of all time.”