Thomson Reuters The global economic expansion has entered its tenth year. Late-cycle booms typically mark the beginning of the end — probably in the form of a downturn. Liquidity, diversification and flexibility are some of the ways investors can shield portfolios. The global economic expansion has already entered its 10th year. With bumpy and brittle growth having given way to a robust and globally synchronized conjuncture, an aging cycle has suddenly become much more cyclical. Alas, late-cycle booms typically mark the beginning of the end.