Bankman is, in addition to his other work, a part-time therapist. Especially interested in anxiety, he has written on the intersection of law and psychology and co-hosted, with Stanford students, a podcast on wellness and the legal profession. He has deployed his psychological expertise at home, to try to keep everyone calm, but the morning after our dinner, as he and I walked around campus, his own anxiety was evident. When I asked what his son’s defense would cost, Bankman said, “Substantially everything we have.” But, he added, sounding melancholic, “that’s what money is for.”

Not long after Sam was born, it became clear to his parents that he was not like other children. He cared little for toys, apart from puzzles, and seemed largely indifferent to amusement parks and birthday parties. One evening before bed, Fried recalled, Sam and Gabriel, who were still in elementary school, started asking her and Bankman questions about divorce. They knew a kid whose parents were getting one, and wanted to know how it worked, and who got what. “We ended up, like, talking about community-property states, and the alternatives to community-property states, and the different ways of dividing up human capital,” Fried said. The discussion went on for more than an hour, and after she and Bankman left the bedroom she turned to him and said, “We are such idiots. They’re interested in what we’re interested in, they’re just a lot younger and more ignorant.” Fried told me, unable to conceal her pride, “And that changed child rearing for us.” They would give their boys fewer amusement parks and more adult conversation.

Still, a few years later, she arrived home from work one day to find Sam, who rarely cried, in tears. “I am so bored I feel like I’m going to die,” he told her. At that point, Fried said, “we went into high gear.” They enrolled him in a Saturday program called Math Circle, where professors taught logic and problem-solving to precocious students. There were further elevated math classes before school. And in ninth grade Bankman-Fried was admitted to a selective summer program called Canada/USA Mathcamp, where, for the first time, he made close friends. Gary Wang, who would become an FTX co-founder, was one of them. “Sam just got inducted into this other world of math and science nerds with passion, and they were his people,” Fried said.

Sam and Gabe were also encouraged to engage in discussions about human rights and foreign policy at their parents’ Sunday-night dinners. Larry Kramer recalled once having a disagreement with the boys and saying something patronizing, like “When you get a little older, you’ll understand.” Later, Kramer said, Bankman took him aside: “They wanted their kids to be treated at the same level as the adults.”

After some hand-wringing about their commitment to public schooling, Fried and Bankman decided that Sam and Gabe would go to high school at Crystal Springs Uplands, a private school that attracted many privileged tech kids, including Steve Jobs’s son. Sam was kind but mostly kept to himself, a former student recalled: “Everyone recognized he was brilliant and super sharp and that school wasn’t challenging for him.”

After graduating, Bankman-Fried enrolled at M.I.T., imagining that he might become a physicist. His plans began to evolve in his sophomore year, when he learned about the effective-altruism movement. Many effective altruists have taken inspiration from the philosopher Peter Singer, who argues that, when more than a billion people in the developing world are impoverished and suffering, spending on luxuries is morally flawed. The E.A. movement has considered how much money it would take to save a single imperilled life (approximately four thousand dollars, by one estimate), and some of its adherents have pursued high-paying careers in order to give most of their earnings to organizations that serve vulnerable groups. The movement appeals to people with quantitative orientations.

In 2014, degree in hand, Bankman-Fried took a job at Jane Street Capital, a trading firm that used mathematical models to find and exploit price discrepancies in different securities markets. The firm hired many programmers and math majors and had a geeky, collegial culture; late-night chess tournaments were common. Jane Street attracted other young effective altruists, among them Caroline Ellison, the daughter of M.I.T. professors, who had graduated from Stanford.

Bankman-Fried told me that the job favored people who could keep track of the many variables influencing the market, and who had the ability to synthesize them and make fast trading decisions, all while managing the computer code designed to execute the trades. He described it as “sort of, like, right at the borderline of humans and computers.”

Bankman-Fried told me that he gave away about half of what he made at Jane Street, though he declined to reveal the amount. Much of the money, he said, went to animal-welfare organizations and to the Centre for Effective Altruism, for grants and movement-building. After about three years, he left Jane Street and briefly worked for the Centre while thinking of starting a company of his own.

The cryptocurrency boom was under way, and hundreds of digital coins were trading on exchanges around the world. Bankman-Fried became interested in the industry after noticing that the prices were often quoted differently depending on which exchange one was using. A clever trader who was proficient in algorithmic programming was well positioned to exploit the differences—say, buying a bitcoin in the U.S., selling it in Japan, and profiting on the spread. In 2017, according to court filings, he and a colleague, Tara Mac Aulay, started trading crypto with their own money on various exchanges. Eventually, others joined in—Ellison; Sam’s math-camp friend Wang, who’d worked at Google; and Singh, a friend of Gabe’s who was working at Facebook. Wang and Singh had also become effective altruists, pledging to donate most of their earnings. The friends made the fund official, naming it Alameda Research.

Under Bankman-Fried, its first C.E.O., Alameda made aggressive bets, often with borrowed money. Because traditional banks wouldn’t lend to crypto companies, the fund had to turn to institutions that catered to crypto, frequently at high interest rates. Alameda’s track record, according to the Wall Street Journal, was inconsistent. A few months after launching, it lost about two-thirds of its assets on a big bet on XRP, a digital currency issued by a blockchain-based payments network. Mac Aulay quit, along with some other employees. Last year, she wrote on Twitter that the departures were in part caused by “concerns over risk management and business ethics.”

Bankman-Fried rebuilt the fund and moved it to Hong Kong. In 2019, though, in the face of regulatory uncertainty, he turned to his dad, who advised his son to set up shop in a place like the Bahamas, which was trying to generate domestic investment by making itself a crypto hub. FTX launched there later that year as an exchange and a trading platform. Alameda provided legitimacy by trading heavily on the new platform—an arrangement that also created conditions for Alameda to receive favorable treatment (possibly by being able to see what trades others on the exchange were making). The C.F.T.C. alleges that FTX gave the fund an “unfair advantage” by exempting it from rules that applied to other users. Bankman-Fried contends that Alameda wasn’t granted preferential access in any way that really mattered: “It didn’t give them the sort of leniency that would fuck over other accounts. We were fairly careful about that.”

In the penthouse, which was valued at more than thirty million dollars and overlooked a yacht-choked marina, Bankman-Fried was living like a fantastically privileged college student, sharing the vast space with Ellison, Wang, Singh, and other employees. He kept odd hours, sometimes napping in a beanbag chair at the office. In 2019, he tweeted about “stimulants when you wake up, sleeping pills if you need them.” Two years later, Ellison tweeted, “Nothing like regular amphetamine use to make you appreciate how dumb a lot of normal, non-medicated human experience is.” (Bankman-Fried has said that he took only prescribed medication, and that his use was on label; Ellison did not comment for this story.)

Most of FTX’s revenue came through fees that investors paid to trade on its platform. CNBC reported that the exchange’s revenue was a billion dollars in 2021. That fall, Bankman-Fried appointed Ellison and Sam Trabucco, a fellow M.I.T. graduate, to become co-C.E.O.s of Alameda, so that he could focus on FTX. Bankman-Fried has said that he didn’t play a role in investing decisions for Alameda after that point, but, according to the C.F.T.C. lawsuit against him, he maintained daily contact with Ellison and Trabucco and stayed intimately involved with the fund.

Bankman-Fried was also becoming a kind of international statesman of crypto. Zeke Faux, a Bloomberg reporter and the author of a book about the industry, “Number Go Up,” told me, “His trick with the media was just being very accessible. If a crypto newsletter needed a quote about Shiba Inu coin prices, he was there. And on the way up this was really effective, and he was able to create this image as the only honest guy in crypto.”

Bankman-Fried told me, of that time, “I was on the path to accomplishing what I wanted to accomplish.” Further affirmation seemed to come when the best-selling author Michael Lewis started hanging around the office and accompanying him to meetings. Bankman-Fried gave Lewis unrestricted access for a book that is set to be published next month.

While audited financial statements for 2021 show a profitable company, FTX, apparently through a loophole in the tax code that applies to cryptocurrencies, was able to report $3.7 billion in carryover losses on its tax returns, greatly reducing its tax bill. Later, accounting experts would see some red flags in the financial statements, including the fact that two different, relatively unknown auditors had prepared them. As one expert speculated on CoinDesk, “With the benefit of hindsight, we can see it perhaps suggested that Bankman-Fried didn’t want any firm to see the whole picture.”

The following year, a murky FTX transaction implicated Bankman-Fried’s parents directly. During the company’s property-buying frenzy, the couple signed a deed to the sixteen-and-half-million-dollar beach house in the Bahamas where they stayed, although they hadn’t paid anything toward it. The bankruptcy suit insinuates that the arrangement was made at their son’s instigation. Bankman-Fried and his parents strongly deny this.

In an explanation that reflects more carelessness about signing legal documents than Stanford law professors typically possess, Bankman told The New Yorker that he and his wife signed the deed in error; that the house was intended to be company property; and that, after belatedly grasping the U.S. tax implications of attesting to owning it, they fulfilled their legal obligations by alerting company lawyers to their concerns. A spokesperson for the couple said, “Outside counsel confirmed to Joe and Barbara that FTX would have all beneficial ownership of the house and agreed to document that in writing.”

Bankman-Fried’s ambitions for his philanthropy grew along with FTX. After the COVID-19 pandemic began, he joined multiple billionaires, including Peter Thiel and Patrick Collison, in funnelling money into efforts to find treatments. Edward Mills, a professor at McMaster University, whose lab conducted one of the largest COVID therapeutics trials in the world, was an FTX beneficiary. He told me that Bankman-Fried wanted to provide funding to hundreds of biotech companies to develop vaccines and treatments, which he hoped could be rapidly tested through an international network of clinical-trial sites. “Sam had a vision of a world free of disease.” Mills said.

At the same time, Bankman-Fried was also becoming one of the largest political donors in Washington, personally contributing some forty million dollars ahead of the 2022 midterms, according to OpenSecrets, a nonprofit that tracks money in politics. He was one of the top C.E.O. donors to Joe Biden’s 2020 Presidential campaign, giving more than five million dollars (an “anti-Trump” donation, he told me). He also made dark-money contributions to Republicans, which he wouldn’t quantify. One of his goals was to counter extremist candidates in Republican primaries, he said, and by keeping his payments under the radar he could avoid the backlash that would ensue if candidates were found to have taken money from a known Democratic donor.