Former UBS trader Kweku Adoboli arrives at Southwark Crown Court in London September 14, 2012. Adoboli, who was arrested a year ago when a loss of $2.3 billion came to light, is charged with fraud and false accounting.

London - A UBS banker accused of gambling away $2.3 billion (1.78 billion euros) told a London court on Monday he did not believe he was a rogue trader.

Kweku Adoboli, 32, told Southwark Crown Court that if what he was doing amounted to gambling, then so did the entire investment banking industry.

Asked by his lawyer how he felt when the prosecution called him a “rogue trader”, he choked back tears and said: “It doesn't feel fair.”

Adoboli stands accused of faking hedge deals, leaving Switzerland's biggest bank exposed to huge losses when the market turned against him.

He denies two charges of fraud and four of false accounting in the period between October 2008 and September 2011.

Adoboli said the losses piled up after more senior UBS traders convinced him to change from a bearish to a bullish point of view in July 2011, expecting upward price movement in the stock market rather than downward sentiment.

“At that stage I broke, I just broke,” he said.

“I should have held onto my conviction of fear of the market.

“At that very point I changed my position. That is why I don't believe I was a rogue trader.”

The strategy switch backfired spectacularly as the European banking sector continued to fall, he said.

“I wish I was a rogue trader, I wish I hadn't listened,” he added.

Adoboli, the son of a Ghanaian former United Nations official, began giving evidence on Friday in a trial which is now in its seventh week.

He said he would rise at 3:00am to start work from home, monitoring the financial markets around the world.

“The purpose of doing all that investigation and analysis is to increase the chance, to increase the level of understanding and reduce the number of things that are going to be surprises when you make decisions about where you think the market is going,” he explained.

“If that is just a calculated gamble, then all investment banking is a calculated gamble.”

Adoboli joined UBS in London in 2003 and moved to its exchange traded funds desk in May 2006. In 2007, he and another more senior trader were managing a portfolio worth $50 billion.

“We were brothers, we did everything together,” Adoboli said.

“We had the same dreams, we had the same desires.

“By this point we all wanted to achieve the same thing, which was to have a successful book.”

Adoboli told the court on Friday that he did his first off-the-books trade in November 2008 - something prosecutors say are “illegally conducted” - holding trades off the ledger until the market rebounded. - Sapa-AFP