This Man's Portfolio Surged 54x in 15 Months Before Collapsing: The Full Story
The name Leopold Aschenbrenner has become a topic of intense discussion in Silicon Valley and Wall Street. The former OpenAI researcher was regarded as being able to foresee the future of artificial intelligence more rapidly than most investors. His AI hedge fund, Situational Awareness, grew from a newcomer with a portfolio of hundreds of millions of dollars to an investment exposure manager worth tens of billions of dollars.
However, the use of significant leverage led to a dramatic end to that growth. Situational Awareness reportedly held assets and exposure of up to US$45 billion, using an exchange rate assumption of Rp18,000 per US dollar. Within days, its value shrank to approximately US$10 billion after the fund was forced to sell its leveraged public equity portfolio. Ken Griffin’s Citadel subsequently entered as a buyer at a discount, according to reports from CNBC International.
This figure refers to the assets or holdings reported by CNBC International. The US$35 billion reduction does not represent all investor cash, but also reflects market price declines, position reductions, and the reduction of exposure previously built using debt. Situational Awareness reportedly utilised leverage of up to approximately 400%. While leverage causes profits to soar during market upturns, it amplifies losses when stock prices move downwards.
It is important to note that Ken Griffin and Citadel did not take over the Situational Awareness company itself. Citadel did not purchase the company name, management team, investor contracts, or its entire asset base. Instead, the firm purchased the public equity portfolio that Situational Awareness was forced to divest to meet margin calls and reduce debt. Currently, Situational Awareness’s public equity portfolio is being sold to Citadel amidst pressure on semiconductor and AI stocks. The fund retains its private investments, most notably its multi-billion dollar stake in Anthropic. Thus, Citadel purchased assets that were forced into sale, rather than acquiring the hedge fund itself.
Aschenbrenner possesses an unusual background for a manager of tens of billions of dollars. The German-born individual completed high school at age 15, later studying economics, mathematics, and statistics at Columbia University, where he graduated as valedictorian in 2021. He previously worked at Future Fund, the philanthropic arm of the crypto firm FTX. In 2023, he joined OpenAI’s Superalignment team to study methods for controlling AI systems that could surpass human intelligence. His career at OpenAI ended in 2024 following allegations of improper sharing of internal information, a characterisation Aschenbrenner denies, stating he was communicating concerns regarding OpenAI’s internal safety.
Weeks later, he published a 165-page manifesto titled ‘Situational Awareness: The Decade Ahead’. In this document, Aschenbrenner predicted that Artificial General Intelligence (AGI) could arrive by 2027, forecasting that tech companies would spend trillions of dollars on data centres, power plants, and AI chips. The popularity of this writing helped him raise capital. In July 2024, he founded the Situational Awareness hedge fund with initial capital of approximately US$225 million from various tech figures, including Stripe founders Patrick and John Collison, former GitHub CEO Nat Friedman, and investor Daniel Gross.
SEC documents reveal how aggressively Situational Awareness expanded its portfolio. However, 13F values should not be directly equated to Assets Under Management (AUM), as these reports only cover specific securities traded in the United States. Short positions, cash, debt, certain foreign stocks, and private investments like Anthropic are not fully visible. Based on SEC filings, the reported portfolio value rose from US$254.8 million at the end of 202_ to US$13.68 billion by March 2026, representing a 13F exposure growth of approximately 53.7 times, or 5,267%.
The most rapid growth occurred in Q1 2025, when the portfolio value nearly quadrupled. After growing by more than 90% over the following two quarters, expansion slowed by the end of 2025 before surging again by 147.9% in Q1 2026. This recent surge was largely driven by put options rather than common stock purchases. The value of common stocks actually decreased by about 1.5% compared to Q4 2025, whereas the value of securities related to put options surged from approximately US$8.9 million to US$8.46 billion. These positions included puts against the VanEck semiconductor ETF and companies such as Nvidia, Oracle, Broadcom, AMD, Micron, TSMC, and ASML.
As of early August 2026, the Q2 2026 13F values are not yet available. The US$45 billion figure reported by CNBC is an estimate of Situational Awareness’s gross assets or exposure in early July, accounting for positions outside the scope of 13F reporting. Therefore, a direct comparison between the Q1 US$13.68 billion and the early July US$45 billion may be misleading due to different measurement scopes. The sale to Citadel occurred in late July, meaning the Q2 filing will likely still show the portfolio before the major liquidation. The full impact of the sale will become clearer once the filings are released.