Citadel Absorbs Situational Awareness Stock Book After Leveraged AI Bets Unravel

Forty five billion dollars at the peak in early July, roughly 10 billion by Thursday's close. That is the arc of Situational Awareness, the artificial intelligence hedge fund built by former OpenAI researcher Leopold Aschenbrenner, which was forced to unwind its entire public equity book this week after heavily leveraged bets on AI infrastructure collapsed, according to CNBC. Ken Griffin's Citadel agreed to buy the bulk of the portfolio in a transaction that Seeking Alpha reported came together in roughly 24 hours.

The sale closes one of the most extraordinary chapters in recent hedge fund history. Situational Awareness reported net returns of roughly 439 percent through the end of June and managed as much as $45 billion at the start of July, according to CNBC. Four weeks of technology selling later, the firm has been reduced to a private investment vehicle anchored by a stake in Anthropic valued at roughly $5 billion.

Margin Calls From Three Prime Brokers

The immediate trigger was mechanical rather than thematic. The fund ran its book at roughly four times leverage, according to multiple reports, and its three prime brokers, Goldman Sachs, JPMorgan Chase and Bank of America, moved on margin as July's technology rout deepened. Bloomberg reported that the banks were working with Situational Awareness as it sought to satisfy margin requirements and reduce positions in an orderly manner.

Leverage of that magnitude converts a routine drawdown into an existential event. At four turns of leverage, a 25 percent decline in gross positions can consume all of the equity supporting them. The fund's concentrated holdings in AI infrastructure names, among them SK Hynix, CoreWeave, Nebius, Micron and Bloom Energy, fell sharply during July's selloff, with several of the names losing a quarter or more of their value over the month.

The damage was compounded by the failure of the fund's hedges. Short positions in software companies, including Adobe, were designed to offset long exposure to chips, memory and data center buildouts. Instead, the software names rallied while the infrastructure longs fell, leaving both sides of the book losing money simultaneously, CNBC reported.

Seoul Circuit Breakers Deepened the Rout

Selling that broke the fund gathered force half a world away from its prime brokers. South Korea's Kospi tripped market wide circuit breakers on July 28 and again on July 29, back to back halts without precedent for the index, according to TechTimes. One overnight session took the benchmark down 10.84 percent, with Samsung Electronics losing 13.39 percent and SK Hynix, one of the largest positions in the Situational Awareness book, falling 14.65 percent, 24/7 Wall St. reported. By late July the Kospi had surrendered roughly 40 percent from its June peak, putting the month on course to be the worst in the index's recorded history.

Damage spread well beyond Seoul. Chip and AI infrastructure stocks worldwide shed more than $1 trillion in combined market value as the selloff accelerated, CNBC reported on July 29, with memory suppliers hit hardest: Micron and Seagate each fell more than 8 percent in a single session, Western Digital lost nearly 7 percent and SanDisk dropped 14 percent. Every one of those tickers sat close to the center of the fund's thesis.

TechTimes traced the reversal to three converging pressures: China's CXMT completing Asia's largest IPO of 2026 with proceeds earmarked for DRAM capacity expansion, Chinese firms beginning domestic production of semiconductor lithography equipment, and renewed questions over whether Nvidia's $250 billion financing guarantee to OpenAI reflects sustainable demand or circular financing. In Seoul, lawmakers linked part of the crash to the May rollout of leveraged single stock products, which had concentrated retail capital in the same names the fund owned, according to 24/7 Wall St.

From 439 Percent Returns to Forced Selling

Aschenbrenner launched the fund in 2024 after leaving OpenAI, converting his widely read essay series, Situational Awareness: The Decade Ahead, into an investable thesis. The premise was direct: compute, memory, power generation and semiconductor supply chains would be systematically repriced as AI capital spending accelerated, and a concentrated, levered portfolio was the correct expression of that view.

For roughly two years the strategy delivered. Returns compounded at a pace few funds of any size have matched, assets swelled toward $45 billion, and Aschenbrenner became one of the most closely watched allocators in the AI complex. The same qualities that produced those results, concentration in a single theme and aggressive use of borrowed money, left the portfolio exposed when the theme reversed. July's rout in AI hardware and infrastructure equities hit precisely the names the fund owned in size, and the leverage did the rest.

The episode also illustrates how crowded the trade had become. When a fund of this scale is forced to reduce, the selling itself pressures the very positions being sold, tightening the margin spiral. That dynamic is why the prime brokers pushed for an orderly resolution rather than competing open-market liquidations.

Reporting across the week traced the sequence clearly. Bloomberg first reported that the fund was unwinding trades and seeking capital after heavy losses on AI and software positions. CNBC followed with sourcing that the liquidation covered the entire public book, not a partial de-risking. By Thursday, Seeking Alpha reported the Citadel purchase was done. The interval between the first margin pressure becoming public and the disposal of a portfolio once worth tens of billions of dollars was measured in days, not weeks.

Backers Who Funded the Ascent

Situational Awareness opened in late 2024 with roughly $225 million, according to derivatives research firm SpotGamma, and its earliest checks came from names that lent the venture instant credibility: Stripe founders Patrick and John Collison, former GitHub chief executive Nat Friedman, investor Daniel Gross and the trading firm Jane Street.

Scale followed performance at a pace almost unheard of for a first time manager. SpotGamma puts the public book near $20 billion by mid 2026, while CNBC reported total assets touching $45 billion at the start of July once leverage and private holdings were counted. Two years separated the launch from the peak; six trading days, by SpotGamma's count, separated the June 30 mark of 439 percent net gains from forced liquidation.

Inside a Portfolio Built on One Thesis

Public filings had already sketched how narrow the book was. SpotGamma's review of the fund's first quarter 13F found the top five positions accounting for 76 percent of a $3.86 billion disclosed long book: Bloom Energy at 22.8 percent, SanDisk at 18.8 percent, CoreWeave at 14.4 percent, IREN at 10.4 percent and Core Scientific at 10.1 percent. That filing captured only US listed longs, a fraction of gross exposure once borrowed money and foreign listings such as SK Hynix were layered on.

Ownership stakes were large enough to move the stocks themselves. Per SpotGamma, the fund held 8.2 percent of Core Scientific's float and between 4 and 5 percent of Applied Digital, CleanSpark and WhiteFiber, sizes at which any forced reduction presses directly on the seller's own marks. Protection consisted of roughly $2 billion notional in puts on the SMH semiconductor ETF and about $1.6 billion in Nvidia puts, instruments so correlated with the longs that they offered little defense when the entire AI complex fell in unison. Core holdings dropped between 27 and 54 percent during July, against a Nasdaq 100 decline of more than 10 percent.

Citadel Steps In for the Public Book

Citadel's purchase of the public equity portfolio resolved the standoff in a single stroke. Seeking Alpha reported that Griffin's $71 billion firm took on the bulk of the public investments, a deal negotiated at speed as the margin pressure mounted. Bloomberg reported that assets at Situational Awareness fell to about $10 billion once the transaction was complete.

For Citadel, the trade follows a familiar template: stepping into a forced seller's book at prices set by distress rather than fundamentals. The firm has both the balance sheet to warehouse the positions and the market infrastructure to work out of them gradually. For the selling fund, a negotiated block sale limited the damage that a disorderly liquidation across public exchanges would have inflicted on remaining investors.

Neither firm has publicly disclosed terms of the transfer, and the discount Citadel extracted, if any, has not been reported. What is clear is that the buyer absorbed exposure to some of the most volatile equities in the market at a moment when few other balance sheets were willing to catch them.

Some traders read the block sale as a clearing event rather than a warning. SpotGamma cited desk commentary celebrating that “the unwind is over,” a view that removing the market's largest forced seller lifts an overhang from the very stocks that had been falling all month.

Anthropic Stake Anchors What Remains

Situational Awareness retains its private position in Anthropic, reported at roughly $5 billion, and will continue operating as a private investment firm, according to CNBC. That stake now defines the franchise. Unlike the public book, a private holding cannot be margined and liquidated on a broker's timetable, which is precisely why it survived the week intact.

Timing explains both the stake's survival and its size. Situational Awareness bought into Anthropic's $65 billion Series H in May, according to SpotGamma, months before the public book came apart. Anthropic has since filed confidentially for an initial public offering at a reported $965 billion valuation, Yahoo Finance reported, and any listing near that figure would reset the value of stakes across the company's investor register.

The Anthropic position also preserves a version of the original thesis. Aschenbrenner's argument was never limited to memory suppliers and data center builders; it centered on the value that would accrue to frontier AI development itself. Whether limited partners who absorbed the public-market losses will stay for that longer arc is an open question, and the fund's capacity to raise new capital after a drawdown of this scale is untested.

Concentration and Leverage Under Scrutiny

The unwind invites comparison to Archegos Capital, whose 2021 collapse inflicted billions of dollars of losses on its prime brokers. The differences are instructive. This time the banks acted while equity remained in the fund, coordinated among themselves, and a single buyer took the book. Goldman Sachs, JPMorgan and Bank of America appear to have escaped without the losses that defined the Archegos episode.

The broader lesson lands on allocators. Situational Awareness posted returns that dominated every league table for two years, and those returns were inseparable from the structure that destroyed the fund's public portfolio in four weeks. Thematic conviction, concentration and four times leverage produce the same outcome in both directions. Investors who chased the fund's performance are now holding claims on a private vehicle a fraction of its former size.

Risk officers across the industry will study the mechanics. Four times leverage on a single-theme book, supplied by three of the largest prime brokerage operations on Wall Street, was extended to a manager whose track record spanned barely two years. That the banks exited without apparent losses reflects faster intervention, not a smaller misjudgment about how much borrowing the strategy could safely carry.

For the AI infrastructure complex itself, the forced sale removes a major source of leveraged long exposure from public markets. Whether that clears the way for steadier pricing or simply confirms how much of the sector's advance rested on borrowed money is the question the next quarter will answer.

Fresh Capital Search Defines the Next Test

Aschenbrenner is not finished raising money. Bloomberg, citing the Financial Times, reported that the firm was seeking fresh capital from investors and lenders even as the unwind proceeded, an effort now directed at sustaining a private vehicle rather than rebuilding a levered public book. Persuading allocators to fund the same manager whose structure just failed will test how much of the franchise's reputation survives the drawdown.

Several markers will show which way the story bends. Situational Awareness must file its second quarter 13F by mid August, handing the public a final snapshot of the book before the sale. Anthropic's IPO timetable will set the value of the surviving stake more decisively than any private mark. In Seoul, legislative scrutiny of leveraged single stock products could reshape the retail flows that amplified July's crash. Early evidence of stabilization has already appeared: South Korean shares rallied on a tech rebound in the closing sessions of the month, Trading Economics reported, the first sign that the forced selling that consumed the fund may finally have run its course.