Mr. Lefevre, who left Citigroup in 2008 and began to work at a start-up boutique firm in 2009 in Hong Kong, insisted that many of the exchanges he published on Twitter were true: "I've been collecting these stories for years."
He said his intent was neither to mock nor glamorize Wall Street. "I do not have an agenda to paint the people or this culture one way or the other," he said, adding that he was "always a cynical banker" when he worked on Wall Street but "I loved it. We did a lot of crazy stuff. It's not like I had a great epiphany along the way."
Still, he said that working on Wall Street was an eye-opener. "I went into investment banking and I saw a group of people that aren't as impressive as I thought they were — or as impressive as they thought they were. They defined themselves as human beings by their jobs."
His Twitter feed has become red meat for industry critics, something Mr. Lefevre said was initially unintentional but later something he tried to stoke. "A lot of times I pander, I'll be honest with you. I pander for retweets," he said, referring to users blasting copies of a tweet to their own followers, multiplying its reach.
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He said his Twitter account had evolved over the last few years: "Early on, I tweeted more about specific people or deals, inside jokes/commentary, and even a few ad hominem attacks. That gave me a certain validation and credibility. But over time, the tweets have been increasingly styled to have a bit more commercial appeal.
"I don't consider it selling out or pandering to a lower common denominator; I think of it more as adapting to what the widest possible audience of people responds favorably to."
Mr. Lefevre, who refused to disclose his location in Texas, started worrying several months ago that his identity would be revealed. He received some emails from friends who had guessed it was him. He also noticed that some Goldman Sachs employees had viewed his LinkedIn profile page; he later removed it.
Now that he has been outed, he said, "it's something that can be embraced. And I certainly don't have anything to hide."
—By CNBC anchor and New York Times writer Andrew Ross Sorkin