"Another common practice on the Investor Desk was to cut and paste details of Citibank's order book on to Bloomberg chats at the request of customers," Stimpson said in his statement.
A Citi spokesman said: "All of the allegations of wrongdoing being made by Mr Stimpson have been investigated and were found to be without merit."
Citi has said Stimpson was dismissed for serious breaches of contract, alleging he shared confidential client information with traders at other banks via electronic chatrooms.
He was dismissed last November in the wake of an industry scandal that resulted in banks paying more than $10 billion in fines for failing to stop traders attempting to manipulate the $5 trillion-a-day forex market.
Stimpson, who described himself as "moderately successful" at his job and "quite anti-social", was strongly encouraged to gather and share more market information with colleagues and traders at other banks, he claimed, in order to have a broader understanding of market conditions to help the bank in its trading.
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Maintaining contacts to gather information became one of his annual goals that would help dictate his year-end bonuses.
"Dude, get yourself on a chat," his then line manager Bob de Groot told him in 2009, according to Stimpson's statement.
"Perry has made a good effort to talk to other participants in the market, he could give a little more effort in sharing information and ideas across the business," is what de Groot wrote in his 2009 year-end review, Stimpson claimed in his statement.
De Groot left Citi in early 2010. De Groot was not immediately available to comment.
In his testimony, Stimpson said Citigroup staff breached confidentiality around some clients and that some senior staff used inside information to trade, in contravention of the bank's own code of conduct.
In his witness statement, Stimpson said Michael Plavnik, then head of the short-term interest rate trading desk, looked to profit from trading euros around that day's "fixing", the daily process of setting what are effectively benchmark exchange rates used by many funds, companies and central banks around the world.
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Plavnik had heard Citi's spot FX desk had a large order to buy euros at the fix. Armed with that knowledge, he bought 200 million euros before the fix to sell them back into the market at the fixing rate, Stimpson claimed in his statement.
"Plavnik has not been found to have committed any misconduct," a Citi spokesman told Reuters.
Plavnik, who has since been promoted to global head of short-term interest rate trading, did not immediately respond to an email requesting comment.
Earlier this week, Stimpson told the tribunal that senior Citi staff traded on insider information ahead of a major merger and acquisition deal five years ago which netted the bank $35 million.
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Citigroup's lawyer Diya Sen Gupta told the court on Thursday: "The allegations were investigated and are not, and were not, substantiated."
Stimpson, who is representing himself, admitted that he had signed Citi codes of conduct, which covered a wide range of issues from ethics to client confidentiality, but barely paid any attention to their content.
The hearing will extend into next week, and Stimpson is expected to testify again and bring his own witnesses on Friday.