Central banks turning off the liquidity spigot: Among the most striking market developments in recent years has been the coordinated efforts by the world's central banks to supply liquidity by purchasing financial assets. Investment Strategist Michael Hartnett points out that since the collapse of Lehman Brothers in 2008, central banks have bought $10.8 trillion in assets, and that liquidity has propelled financial markets all over the world.

That phase, as Citi's Matt King warned two months ago, is ending. 

Now it appears that we are on the cusp of global synchronized monetary tightening, according to Hartnett. Central banks in the US, Canada and China have raised rates this year, while the Bank of England has stopped asset purchases and the European Central Bank is on track to end its asset purchases in 2018. Moreover, the reduced pace of re-investment that the Fed has outlined would reduce the size of its balance sheet by $2 trillion by the end of 2022.