Largest loss caused by a rogue trader

What to remember

The term rogue trader covers an employee who has the right to trade for a company but goes further, placing trades the employer never approved. The costliest case involves Jérôme Kerviel, a trader at Société Générale from 2000 to 2008: the loss linked to his trading reached $6,900,000,000, or €4.9 billion.

The positions were on European stock index futures, built up between 2006 and 2008. The loss came to light at Société Générale in January 2008, when the bank unwound positions worth roughly €50 billion at the time, in the middle of the economic crisis.

For a sense of scale, another well-known case is that of Nick Leeson, whose unauthorized investments in index futures contracts led in 1995 to a US$1.3 billion loss, enough to bankrupt Barings Bank, a centuries-old financial institution.