A former UBS banker who cost the Swiss firm more than 2 billion Swiss francs and ended the CEO career of Oswald Gruebel has warned that rogue trading scandals at banks «can absolutely happen again.»

Kweku Aboboli was convicted of fraud and sentenced to seven years after he was found to have traded illicitly and concealed his risk exposure, which ultimately exploded in 2011 into the largest fraud in British history.

Today, Adoboli, who is 36 and has lived in Britain since the age of 12, is banned from working in financial services, but speaks for free at banking compliance conferences. Fighting deportation to Ghana, where he was born, he lives with friends in Edinburgh.

Investment Banking Culture

Adoboli said he believed rogue trading incidents could «absolutely» happen again because the culture of investment banking is unchanged to 2012, when he was sentenced.

«I think the young people I've spoken to, former colleagues I have spoken to, are still struggling with the same issues, the same conflicts, the same pressures to achieve no matter what,» Adoboli told the BBC in his first broadcast interview.

Risk vs Profit

Bankers are required to take risks and generate profits, particularly in an environment where investors are desperately hunting for yield.

«And if investment banks continue to chase the same level of profitability as they have in the past, the only way to generate those profits is to take more risk.»

Pushing Boundaries

Adoboli has maintained that others at UBS knew what he was up to, an allegation the bank has denied. No charges were brought against other UBS staff in connection with the scandal.

The one-time trader also argued that banks consistently pushed for high profits, leading traders into conflict over how far to push boundaries.

«And where the conflict comes is where people fall into this grey zone, and so I think it can absolutely happen again,» he said, adding that this is especially true if predictions of another financial crisis in coming years pan out.