Kindleberger observes in "Reaching for yield"(p. 82), financial history offers many examples of times when falling yields on British consuls and other relatively safe investments generated speculative excess, followed by crash.

FORBES: Side lines

By contrast, by removing excess liquidity, the central bank can cause the sudden collapse of speculative excess, and it can also hurt healthy recovery or growth by constricting the money supply.

FORBES: Anna Schwartz, Monetary Historian, RIP

The strongest argument for a revaluation now is not that the yuan is undervalued, but that an adjustment would halt speculative capital inflows and so mop up the excess liquidity.

ECONOMIST: China's economy

The excess amount of easy money causes prices of assets such as equities or property to increase, which reinforces speculative tendencies.

ECONOMIST: Thailand and the Rohingya