BBC: The current market jitters are centred on disturbances in the world's credit markets. Worries about the viability of sub-prime mortgage lending have spread around the financial system, and the central banks have been forced to pump in billions of dollars to oil the wheels of lending.
But what happened in previous financial crises, and what are the lessons for today?
There have been a growing number of financial crises in the world, according to the International Monetary Fund (IMF).
Among the key lessons of previous major financial crises are:
• Globalisation has increased the frequency and spread of financial crises, but not necessarily their severity
• Early intervention by central banks is more effective in limiting their spread than later moves
• It is difficult to tell at the time whether a financial crisis will have broader economic consequences
• Regulators often cannot keep up with the pace of financial innovation that may trigger a crisis.
Financial Crises: Lessons from History By Steve Schifferes
THE TELEGRAPH:
Shares fall as US house prices in record nosedive By David Litterick, New York
Subprime Crisis
Business Comment: US housing crash reminds us we're due a correction By Richard Fletcher
Mark Alexander