An alleged rogue trader accused of Britain's biggest fraud wept today as he told a jury he was trying to cover millions of pounds worth of losses incurred at the bank he called his "family".
Kweku Adoboli, 32, is accused of gambling away £1.4 billion while working for Swiss bank UBS during the global financial crisis.
At one point he was at risk of causing the bank losses of 12 billion US dollars (£7.5 billion), jurors at Southwark Crown Court were told.
Adoboli broke down in tears as he gave evidence for the first time in his trial, in which he claimed his off-book trades were to cover 40 million dollar (£24.9 million) annual losses of his portfolio of companies from 2008.
The court heard that by 2007 Adoboli, aged just 27, and a more senior trader, John Hughes, 25, were in charge of a portfolio of companies with assets of 50 billion dollars (£31.1 billion).
"Our book was massive. A tiny mistake led to huge losses. We were these two kids trying to make it work," he said.
Adoboli, wearing a dark suit and red tie, denied he was a "gambler" and said his knowledge of UBS's systems did not result in "fraudulent behaviour".
Fighting back tears, he said: "It's hard to find the words to describe the relationship I had with UBS as an organisation.
"It isn't about a bank. It was about what I thought was my family, considering how much (I) neglected my real friends and family.
"Every single bit of effort I put into that organisation was for the benefit of the bank, the people around me and the book I worked on.
"If I was not so proud to work for UBS, I would never put so much effort trying to convince them that we could achieve something at this bank."
He added: "To find yourself in Wandsworth Prison for nine months because all you did was work so hard for this bank ...", before stopping as he broke down in tears.
Adoboli is facing two counts of fraud and four counts of false accounting between October 2008 and last September, allegedly gambling away the money on high-risk illegal trades aimed at boosting his annual bonuses and job prospects.
The former public schoolboy, of Clark Street, Whitechapel, east London, worked for UBS's global synthetic equities division, buying and selling exchange traded funds (ETFs), which track different types of stocks, bonds or commodities such as metals.
The court has heard that at one point he was at risk of causing the bank losses of 12 billion US dollars (£7.5 billion).
Adoboli told the court he feared UBS would not survive 52 billion dollar (£32.3 billion) losses incurred in 2007-08 as the banking crisis took hold.
"The effect on the organisation was incredible," he said.
"There were times we thought there was no way the organisation would survive. I grew up with UBS. I felt very loyal to UBS.
"What could we do to help this organisation survive this incredible crisis?"
Ghanaian-born Adoboli enjoyed a rapid rise at UBS after completing an internship while a student at Nottingham University in 2002, the court heard.
He secured a job with the bank in London in 2003, working as an analyst with the firm's Swiss settlement team before being promoted to a trade support analyst.
He later become a junior trader with UBS's hedge fund services before becoming a trader on the company's ETFs desk in May 2006.
The trial has previously heard that Adoboli walked out of the bank, saying he was going to the doctor's, and an hour later sent a "bombshell" message from his personal email account.
In the message to colleagues, including William Steward, a co-worker who was checking his deals, he admitted that trades he had entered in the ledger were not real and some were "off-book", which prosecutors claim meant they were "illegally conducted and hidden trades".
Adoboli said he had hoped to make his losses back, but had "clearly failed".
The message read: "I am deeply sorry to have left this mess for everyone and to have put my bank and my colleagues at risk."
Adoboli hid his off-book trades in a fund called an "umbrella", the court heard.
Giving evidence, the defendant said his first off-book trade in November 2008 incurred a 400,000 dollar loss.
"I sat down and looked at the market and thought about what trade I could do to offset that loss," he said.
A 40 million dollar profit was created in the umbrella fund in 2009-10, Adoboli added.
He denied he was "gambling" with his trades as they were based on his "experience in the market".
Asked by his defence lawyer Paul Garlic QC what his long term intention was, Adoboli replied: "To be able to generate a profit, a pot of money, that gave us the confidence to continue to take these type of considered decisions."
A number of colleagues were aware of the umbrella fund by early 2011 and did not raise concerns, he said.
"Nobody once turned around and said: 'You know what Kweku, that is dishonest, stop doing it'," he said.
The court heard Adoboli included the phrase "ella, ella, ella" in one email to a colleague, referring to popstar Rihanna's single Umbrella.
Asked whether he believed his actions countered UBS's company policy, he said: "I don't believe what we were doing was illegitimate."
"We are the ones on the frontline of the business taking decisions that generate profit for the business."
The trial was adjourned until Monday.
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