John Rusnak was Allfirst's star trader. Since joining the bank in 1993, he had impressed his superiors with his ability to make large profits in dealing currencies, mainly by betting against the Japanese yen.

Things began to go badly wrong in 1997. He had made huge bets that the yen would rise against the dollar, but it began to slide. His trading had become reckless as he failed to guard the bank against large losses. Normally traders would also make a reverse bet, taking out a contract with another financial institution which it could use to cancel any losses.

It was in an attempt to cover up his mounting losses that Rusnak began to falsify documents to make it appear he had hedged his currency bets. He created a file on his personal computer called "fake docs" and printed letters which appeared to show that he had contracts in place which cancelled out his losses.

Meanwhile, he manipulated the controls designed to catch any irregularities. In 1997 he concealed losses of $29.1 million (€29.89 million). Over the next four years, his losses swelled as he made bigger and bigger bets to try to win back what he had lost. By 2000 some $300 million had slipped through his hands. The money had gone to other financial institutions which had collected on his bad calls.

In the last two years before he was caught, he used more daring means to raise money to support his trading, selling so- called deep-in-the-money options to Citibank, Bank of America, Deutsche Bank, Merrill Lynch and Bank of New York. The $691.2 million loss consisted of $291.6 million in bogus assets and $397.3 million in unrecognised liabilities.