Politicians have blamed the troubles at the banks on bad risk management. And they've promised to bring new rules to bear on those taking chances with other people's money.
Risk: it's a board game, it's a Bollywood movie and, if you believe the leaders of the G20, it's why we're in the middle of a global financial crisis.
Did bankers and traders take big risks with our money? If so, did they know that they were doing?
Would stronger regulation curb risky behaviour or will it just stifle innovation?
In this documentary, Claire Bolderson investigates the point of risk, what went wrong, and how to make it right.
Claire talks to a banker who was among the first to use some of the complex financial instruments blamed for the current crisis and a 90-year-old risk manager who's seen it all - good times and bad.
One of the world leaders asking for greater control on risk is French President, Nicholas Sarkozy. "Laissez-faire c'est fini", he says in a speech. The time of non-interventionism and the all-powerful market is over.
Do the British and Germans agree?
Across the pond, the Americans don't necessarily want tighter rules on risk.
The US perspective is that risk cannot be regulated away. When people know about risks, they can manage them better. The market will do the right thing if the information is good.
Is the key to the problem greater transparency?
Daniel Kahneman, a behavioural psychologist who studied risk and won the Nobel Prize in Economics without ever taking a course in economics, talks about a "dread element" - that people are more afraid of risks that cannot be seen.
Kahneman and other experts explain what people are thinking when they take risks, and why those who think they know what they are doing sometimes get it spectacularly wrong.
The question then becomes what to do about it in financial markets.
Claire seeks answers from businesses leaders, regulators and thinkers on either side of the Atlantic.First broadcast 31 December 2008