In August 2022, Ellison became the head of Alameda Research, Bankman-Fried's trading firm that was closely intertwined with his fallen crypto exchange, FTX. By November, as FTX swiftly spiraled into bankruptcy, Ellison began to draw attention for her role in overseeing the risky bets Alameda took with customers' funds.
And now the same judge who sentenced Bankman-Fried to 25 years in prison earlier this year will hand down Ellison's sentence on Tuesday. Prosecutors and Ellison's lawyers, though, have asked for her to spend no time behind bars due to her cooperation with the government.
"Ellison stood out not only for the speed of her cooperation, but for her consistent candor beginning in her very first meeting with the Government," prosecutors wrote in their sentencing letter. "She accepted full responsibility from her very first proffer and did not minimize or shift blame."
Former federal prosecutors have told Business Insider that it's likely Ellison won't be locked up.
Here's what we know about Caroline Ellison.
Ellison primarily grew up in Newton, Massachusetts, a suburb of Boston.
Ellison and her two sisters "definitely got exposed to a lot of economics" growing up, she told Forbes. When Ellison was 8, she gave her father an economics study analyzing stuffed animal prices at Toys 'R' Us for his birthday in lieu of a card, Forbes reported.
Ellison exhibited a special passion for mathematics from an early age.
And her father supported her interest in the subject, too.
He encouraged her and her siblings to enter math competitions — which Ellison continued throughout middle school and high school, according to the Washington Post.
Ellison graduated from Newton North High School in 2012, and went on to Stanford University, where she studied mathematics.
Ellison said she picked Stanford because she wanted to get away from Boston and "try something different," she said on The FTX Podcast in 2020.
Though she contemplated studying linguistics, political science, or computer science when she was a freshman, she said on the podcast that she opted for mathematics because there were more opportunities to take other classes on the side.
Ellison also began exploring effective altruism in college.
In later years, the extent to which Ellison believed in EA has become unclear. She seems to have renamed her Tumblr blog from "worldoptimization" to "Fake Charity Nerd Girl" at one point.
Ellison went on to work at the trading firm Jane Street after college.
Ellison spent around 18 months as a trader on Jane Street's equities desk and said on the FTX Podcast that she "loved it."
By 2018, Bankman-Fried had already launched a crypto trading firm called Alameda Research and persuaded Ellison to join the firm.
The switch from Jane Street to Alameda was initially challenge for Ellison, she has said.
"I wanted to be an expert on everything, but there was still lots of stuff in the crypto world that I knew nothing about," she said on The FTX Podcast, adding that she "had to learn a whole new set of intuitions."
After Bankman-Fried established the crypto exchange, FTX, in 2019, Ellison began taking more responsibility at Alameda.
Ellison and her colleague Sam Trabucco took over from Bankman-Fried as co-CEOs of Alameda in late 2021, and the duo were featured in Forbes' 30 Under 30 list in 2022.
However, Bankman-Fried "remained the ultimate decision-maker" at Alameda, directing investment and operational decisions, the Securities and Exchange Commission has said.
"Though Ellison made some trading decisions, she frequently consulted with Bankman-Fried, particularly about strategic issues and significant trades," the regulator said in an SEC complaint.
Bankman-Fried moved his crypto operations from Hong Kong to the Bahamas in 2021 where Ellison was among the 10-person crew of FTX and Alameda employees who all lived together.
"In a lot of ways I don't really have a soul," Bankman-Fried once wrote to Ellison, according to Lewis. "There's a pretty decent argument that my empathy is fake, my feelings are fake, my facial reactions are fake. I don't feel happiness. What's the point in dating someone who you physically can't make happy?"
Ellison and the other housemates reportedly shared a therapist named George Lerner, who also helped employees navigate career decisions, office drama, and their dating lives.
He has also said the collapse of FTX was "devastating" and that its employees felt "like a family."
Ellison largely remained out of the limelight as FTX rose to fame.
"Caroline didn't have a lot of gravitas," one former staffer told The Financial Times, who thought she was "an intern" when they first met.
Ellison's compensation at Alameda also remains a subject of continued inquiry.
Court documents filed last year show that Ellison received about $6 million as the CEO of Alameda, while her colleagues, including Nishad Singh, FTX's former director of engineering, and Zixiao "Gary" Wang, received hundreds of millions.
Meanwhile, Bankman-Fried himself transferred $2.2 billion into his accounts, per those filings.
On her Tumblr, worldoptimization, she said that crypto was "mostly scams and memes when you get down to it" but she's also seen "a real and pressing need for crypto."
She also compared the polyamory in the Bahamas house to an "imperial Chinese harem," noting on worldoptimization, that there was an established hierarchy and everyone knew where they fell within it.
Ellison is also reader who often posted book reviews on her Tumblr and is a Harry Potter fan.
Ellison said on The FTX Podcast that her parents read the first Harry Potter book aloud to her when she was just 3, and she read the second book by herself at the age of 5.
Her literary tastes, however, range far and wide. Among the last books she reviewed on worldoptimization are "The Golden Enclaves" by Naomi Novik and "Venomous Lumpsucker" by Ned Beuman, and she also appeared to enjoy the work of journalist Matthew Yglesias.
In August 2022, Sam Trabucco stepped down as co-CEO, and Ellison began to run Alameda on her own.
Ellison said working with Trabucco was "an incredibly formative experience" in a post on X at the time.
Bankman-Fried had told Ellison to publicly reassure investors about Alameda's financial stability. In the post she noted that the balance sheet was only for "a subset of our corporate entities" and that "we have > $10 billion of assets" and "hedges" that weren't listed.
Ellison pleaded guilty to seven charges in the collapse of FTX, including wire fraud, according to her December 2022 plea agreement with the Southern District of New York
She wrote in 2022 that, "At the end of the day I can't wait to go home and turn off my phone and have a drink and get away from it all," according to the report. She also noted that her romantic history with Bankman-Fried made Alameda "too associated with you in a way that was painful."
Ellison also seemed to doubt about her capacity to lead Alameda, noting that she struggled with "leadership" and "decisiveness" in a document from April 2022, according to the Times. "Running Alameda doesn't feel like something I'm that comparatively advantaged at or well suited to do," she wrote, the Times reported.
In a recording of an all-hands meeting that prosecutors shared in the case against Bankman-Fried, Ellison blamed him for manipulating customer funds.
"Alameda will likely wind down once we can, like, repay all of our creditors and sort of wind down a bunch of our, like, whatever remaining obligations we have," Ellison said in the meeting, according to prosecutors. When an employee asked who decided to use FTX customer deposits, Ellison responded with "Um…Sam, I guess," according to the filing.
In the filing, prosecutors also shared a memo that Ellison wrote, "Things Sam Is Freaking Out About," which they said details her thoughts on the scheme between FTX and Alameda.
They plan to introduce the memo into the trial as evidence that Ellison was acting on Bankman-Fried's behalf, prosecutors said.
Ellison testified as a key witness in the trial against Bankman-Fried.
Ellison's testimony in the high-profile trial spanned three days in October 2023 in a Manhattan courtroom. She detailed how she and Bankman-Fried used Alameda Research to invest billions of dollars worth of assets covertly diverted from customers of FTX, the cryptocurrency exchange he controlled.
She told jurors how she worked with Bankman-Fried and other members of his inner circle to defraud the customers and investors of FTX.