Investors money is tied into these accounts, and so the interest paid can fall if the inflation rate drops in subsequent months.

BBC: Inflation cutting savers' options

This contributed to huge and ongoing drops in Greek output: GDP is set to fall by around 5% this year.

ECONOMIST: The IMF needs to change tack if Spain asks for a bail-out

In the SPDR Gold Trust prospectus, for example, the trust can liquidate when the dollars in the trust fall below a certain level, if the net asset value (NAV) drops below a certain level, or by agreement of shareholders owning at least 66.6% of all outstanding shares.

FORBES: The Gold Showdown: ETFs Vs. Futures

The fact that some markets, including Wall Street's, recovered quickly suggests that the fall was based on short-lived copy-cat behaviour by traders worried by steep share-price drops in Hong Kong, rather than by important new information about the value of American shares.

ECONOMIST: All fall down | The