London fix

The 4pm London fix, in particular, is taken as the gospel exchange rate for a wide array of currencies.

The Times' question was inspired by the fact that at the close of market Friday the London fix was $423.

If we are in need of a "London fix," a ten-minute walk takes us to a daily bus service to central London.

The pricing of gold and platinum numismatic products will now be directly related to the average weekly London fix prices for the metals, the Mint said.

None has detailed its suspicions, but concerns reportedly centre around abnormal movements ahead of a widely-used daily snapshot of exchange rates, known as the 4pm "London fix."

The percentage of the values for the gold and silver production is based on the Q3 2008 average London PM fix for gold and the London fix for silver.