(Bloomberg) -- Not long ago he was playing polo on the Connecticut Gold Coast -- a dashing young Wall Streeter charging hard for a winning shot.

But on April 22, with his nerves on edge, William Tomita reached for the Xanax: He was due in federal court that Friday to plead guilty in the Archegos trading debacle and to formally turn on his longtime boss, Bill Hwang. Tomita was so distressed to speak publicly, he would tell the judge, that he had to take anti-anxiety medication first.

Before him to the Manhattan courthouse had come his colleague Scott Becker, down from his home in Goshen, a quiet New York town named after the biblical land of plenty. Becker, too, had arrived to plead guilty and officially flip on Hwang, the enigmatic investor accused of masterminding a vast, criminal scheme to mislead banks and manipulate markets.

Until that moment, Tomita and Becker were virtually unknown in financial circles, at least beyond the insular domain of Hwang’s Archegos Capital Management. Now they will play a key role in prosecutors’ case against Hwang and Patrick Halligan, the former chief financial officer of the secretive investment firm. The once-trusted lieutenants could become star witnesses.

Few have been closer professionally to Hwang for longer than Tomita, his top trader, and Becker, his risk manager. With those two at his side, Hwang amassed one of the world’s great fortunes in virtual secrecy, only to lose it in a public spectacle of recklessness, hubris and, prosecutors assert, fraud and more. Tomita and Becker have cut deals in hopes of avoiding prison, or at least shortening their terms. Hwang and Halligan have pleaded not guilty to a range of charges, including racketeering conspiracy brought under statutes typically associated with mob bosses.

Who are the Archegos insiders who’ve turned on Bill Hwang? Like their boss, Tomita and Becker have flown under the radar for years. Both 38, they’ve spent almost all of their careers working with Hwang, first at Tiger Asia Management, where Hwang initially ran into trouble, and later at Archegos, whose collapse last year sent shock waves through global finance.

Despite playing key roles at Archegos -- which at one point amassed a staggering $160 billion position in stocks, according to prosecutors -- their public resumes are practically nonexistent. Neither appear to have active LinkedIn accounts. A Google search turns up almost nothing before Archegos imploded and made headlines around the world. Their lawyers didn’t return calls and emails seeking comment.

The prospect of a courtroom drama replete with accusations and betrayals is bound to captivate Wall Street. The prosecution is depending on the pair to provide an inside account of supposed lies and deception. The defense will almost certainly question why Tomita and Becker have turned on their former boss. Hwang and Halligan are due back in court May 19.

Jackson R. Sharman III, a white-collar defense lawyer, said one defense strategy would be to argue that the two cooperating witnesses are merely trying to cover up their own mistakes or wrongdoing, and that while Hwang may have lost a fortune, he didn’t intend to commit any crimes. The likely argument, according to Sharman: “There’s no smoking gun, there’s no fingerprint.”

What’s more, the Archegos debacle fractured ties between Hwang and some of his former staffers, who have fought to recoup deferred compensation that was tied up with the firm, Bloomberg has reported. Many Archegos employees were required to invest 25% or more of their bonuses with the fund and collectively lost millions of dollars, according to the US. Becker and Tomita elected to have a “substantial” portion of their money deferred, the SEC said.

But the duo’s testimony will be crucial for prosecutors to obtain a conviction against Hwang because evidence in the indictment of his knowingly and intentionally violating the law “is exceedingly thin,” said Justin Danilewitz, a partner at Saul Ewing Arnstein & Lehr and former assistant US Attorney. Without detailed independent corroboration, “the government’s job is tougher here.”

Tomita and Becker certainly have a lot to tell. Both spent almost a decade and a half working for Hwang. Tomita, the son of a prominent Chicago surgeon, graduated from Northwestern University in 2006 with a degree in economics and international studies. After a brief stint at Lehman Brothers before the investment bank’s 2008 collapse, he went to work for Hwang’s hedge fund, Tiger Asia Management. A few years later, the firm pleaded guilty to wire fraud related to illegal trading in Chinese stocks and shut down.

While Tomita wasn’t named by US authorities, Hong Kong regulators charged him with helping Hwang commit insider trading. He was cleared in 2013, with regulators saying he was just a junior staff member acting on Hwang’s instructions.

Despite the close call, that year, Tomita stayed with his boss as he opened his family office, Archegos.

There, prosecutors contend, Hwang called the shots and relied on Tomita to execute trades. Tomita also was one of Hwang’s primary contacts when communicating with about a dozen counterparties, according to the government.

When not trading for Archegos, Tomita often played the No. 2 position on polo fields including one in Greenwich, Connecticut. With a half-point handicap, on a scale of -2 to 10, his typical job involved setting up goals for the No. 1 player and taking his own shot after a missed try. 

One player who practiced with Tomita said he came across as polite and deferential -- almost unusually so in a sport known for aggressive and even dangerous play. Tomita avoided big risks on the field, said this person, speaking on the condition of anonymity. After Tomita filled in for this player in one game, the trader followed up with a personal Thank You note. 

Tomita has also been seen on the polo fields near Palm Beach, Florida, where he has a white mid-century house hidden behind tall hedges that’s a block from the ocean. No one answered the door there this week. 

Tomita has pleaded guilty to five counts, including conspiracy, fraud and market manipulation, according to court records. Each crime carries a maximum of 20 years in prison. Tomita is free on $500,000 bond.

At the April hearing in front of Judge Laura Taylor Swain, Tomita admitted under oath that, as head trader from March 2020 to March 2021, he made trades intended to build market power in particular stocks and used financial derivatives to mask the size of Archegos’s positions from other traders and from counterparties.

He also made false statements to banks and brokers that allowed Archegos to trade on margin and convince them to enter into swap agreements with the firm.

“I agreed with Bill and others to carry out the business of Archegos through a pattern of manipulating the prices of securities and deceiving counterparties,” Tomita said, standing and reading from a prepared statement.

The day before, Becker had pleaded guilty to three criminal counts of conspiracy and fraud. Becker, who graduated summa cum laude from Manhattan College with a degree in accounting and finance, told Swain that he started on Hwang’s operations team at Tiger Asia in 2007. He told the judge that he lied to other financial institutions about Archegos’s holdings as part of a scheme to get them to extend credit or take part in swap transactions.

“For example, in 2021, I falsely represented to certain financial institutions that Archegos’s largest position was approximately 35% of its net asset value when, in fact, I knew the largest position had grown to significantly higher -- to a significantly higher percentage than that,” Becker told the judge. 

“And when you did these things, did you know that what you were doing was wrong and illegal?” Swain asked Becker.

“Yes,” he replied. Becker is free on $300,000 bond.

While Tomita cut a striking figure on various polo grounds, Becker appears to have lived a quieter life in Goshen, a 75-minute drive north of Manhattan. His tan two-story colonial-style home, with warm red shutters, sits on a large, grassy hill speckled with spring dandelions. Reached there after his hearing, he declined to talk about his background, Archegos or the case against Hwang and Halligan.

“I have a young family,” Becker said, looking over his shoulder into the house. “Please don’t come back.”

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