HSBC's global head of foreign exchange trading Mark Johnson was arrested and charged with fraud on Tuesday.
The US Department of Justice has accused him of 'front-running', where brokers benefit illegally from a client's trade.
The amount of money reportedly involved was more than $3 billion (£2.3bn) – with an alleged profit for Johnson and his fellow-accused, Stuart Scott, of around $3m (£2.3m) – surely the kind of sum that would be instantly noticed, right?
Wrong. Sadly, some financial institutions have a murky past as far as misplacing enormous sums of cash goes.
Scroll through the gallery above to view some of the biggest fraud stories of recent years