Spreadsheets: a tool you can trust?

For years, the spreadsheet has been an indispensable tool of financial institutions, where it has been used in almost every department – from the trading desk to human resources, finance and accounting.

But spreadsheets are only as perfect as their users – which is to say they are especially vulnerable to both accidental errors and to malicious meddling.

Take the case of John Rusnak, the rogue trader formerly employed on the currency desk at Allied Irish's Allfirst bank. Rusnak managed to hide $