You’ve probably heard of Ken Griffin’s astronomical success as founder and CEO of Citadel. However, his investment empire extends far beyond hedge funds. Ken Griffin’s investment portfolio spans technology startups, real estate ventures, and emerging markets across multiple continents. Want more details about the companies Ken Griffin owns or invests in? Let’s explore.
Citadel’s hedge funds and accounts hold a huge portfolio with over 14,300 different stock positions spread across various sectors. However, a handful of large positions dominate its public-equity investments. Key examples include:
Citadel also invests in broad market ETFs to diversify. For example, as of mid-2024, it held about 5.6 million shares of the SPDR S&P 500 ETF Trust. That’s approximately $3.05 billion. Also, they had 3.3 million shares of Invesco QQQ, which is worth around $1.58 billion.
These ETF positions give Griffin indirect exposure to all major U.S. large-cap stocks (SPY) and to the Nasdaq-100 tech stocks (QQQ). Together, these index funds alone account for multiple billions under management.
Beyond broad market indexes, Citadel and Griffin himself have reported sizable stakes in certain individual firms. In the public markets, filings show:
Citadel Advisors LLC disclosed owning 1.319 million Class A shares of Bakkt, equal to 8.7% of outstanding stock. Mr. Griffin is deemed to own those shares beneficially. Bakkt is a bitcoin futures and crypto platform, and Citadel’s stake was worth on the order of $10-20 million. That’s about 8.7% of the company.
Citadel announced it held about 3.167 million shares of oncology drugmaker MEI Pharma as of Q3 2025. This was 9.75% of MEI’s stock. Griffin’s beneficial ownership was essentially the same, about 9.99%. This position represents close to a 10% ownership stake in MEI Pharma.
In mid-2024, Griffin’s Citadel fund raised its stake in Sphere Entertainment to roughly 5.3% of the company. Sphere Entertainment is the public company behind the MSG Sphere concert venue in Las Vegas. Griffin went from a 1.6% position, with 0.6 million shares, to 5.3% with 1.5 million shares in 2024, giving Citadel a multi-million-dollar stake.
Citadel’s market-making arm, Citadel Securities, disclosed in February 2023 that it owned about 5.5% of Silvergate’s shares, which is worth roughly $25 million. Silvergate was a crypto-focused bank. Citadel Securities reported this as a passive investment. The firm later lowered its stake as Silvergate faced troubles.
In mid-2025, Citadel Securities participated as an investor in Digital Asset’s $135 million funding round. Digital Asset is a blockchain software company (private). Citadel Securities joined lead investors (DRW and others) in financing this startup, reflecting Griffin’s interest in blockchain technology.
NOTE: These examples illustrate that Griffin, via Citadel and Citadel Securities, has stakes both in traditional and emerging companies. Aside from public stocks, he privately owns Citadel LLC and Citadel Securities outright. He has also been involved in private deals, e.g., crypto startups and fintech. For instance, Griffin and his firms have invested billions in venture rounds or backed new enterprises, such as digital-asset platforms. In many cases, exact stake details aren’t public, but his participation is noted in press releases and filings.
In summary, Ken Griffin’s investment portfolio is vast. Through Citadel, he owns multi-billion-dollar positions in various financial firms, tech giants, medical device companies, and more. He also holds significant blocks of ETF shares (SPY, QQQ) worth several billion dollars each.
Furthermore, Citadel/Griffin has disclosed notable stakes 5-10% range in smaller companies like Bakkt and MEI Pharma, and has entered private rounds for startups like Digital Asset. All told, the Griffin/Citadel portfolio combines mainstream blue chips and cutting-edge ventures. It illustrates why Griffin is one of the world’s top investors.
Ken Griffin’s investment portfolio is deeply intertwined with Citadel and Citadel Securities—both private firms he largely or wholly owns. He doesn’t separate personal wealth from investments made through those companies. Technically, many of his high-profile stakes are held via Citadel Advisors or Citadel Securities, and they are reported under those names. So while Griffin is behind the decisions, the public sees the firms’ filings and disclosures rather than his personal holdings.
Recent filings show Citadel holds significant equity in a diverse array of listed companies—often ranging from hundreds of millions to a couple of billion dollars per position. As of early to mid-2025, some of the largest include:
These holdings reflect a broad mix from financials and tech giants to healthcare and consumer brands.
Yes. Griffin, particularly through Citadel Securities, has been involved in private and venture-style investments. For example, they participated in a $135 million funding round for Digital Asset, a blockchain software company, in mid-2025. These investments typically lack public stake disclosures, but they signal interest in emerging technologies, especially in fintech and blockchain.
As the founder, majority owner, and active manager of Citadel, he exerts substantial influence over strategic investment choices. Citadel consists of various specialist trading teams, risk analysts, and portfolio managers. But overall direction, capital allocation, and large-scale positions often reflect his overarching philosophy and leadership.
Yes. Given the scale of Citadel’s holdings, especially its multi-billion-dollar positions and large ETF allocations, its buying or selling can move markets. Moreover, Citadel Securities’ role as a market maker gives it an outsized ability to influence liquidity and pricing in certain equities, especially during volatile periods.
Many are, thanks to mandatory disclosures:
Public information captures most public-market stakes; private deals rely more on media or venture tracking.
Citadel invests across sectors and asset types, including financials, tech, healthcare, consumer goods, ETFs, and crypto-related ventures. On one hand, its holdings in giants like Apple, Amazon, and Schwab offer blue-chip stability. On the other hand, ETF positions provide broad market coverage. Add to that the smaller, concentrated bets in emerging names and private rounds, and the result is highly diversified with both core positions and opportunistic plays.
Typically not:
Retail investors can buy similar ETFs (like SPY or QQQ) or large-cap stocks, but bear in mind the timing and scale differences.
To monitor Citadel’s evolving portfolio, you can check:
His ownership in Citadel Securities, a market-making firm, is separate from Citadel LLC, the hedge fund. However, both entities bear his strategic imprint. Citadel Securities may occasionally make passive equity investments like the 5.5% stake in Silvergate Capital, but its operations and capital are separate from the hedge fund’s trading accounts.
Yes. Citadel manages multiple funds and accounts, each focused on distinct strategies like equity, quantitative, fixed income, commodities, macro, etc. Filings aggregate these across the umbrella of Citadel Advisors or associated entities. While public filings don’t always break down holdings by fund, the diversity reflects a modular structure where each team executes a particular play based on its mandate.
ETFs like SPY and QQQ allow Citadel to manage broad-market exposure efficiently. They act as building blocks for portfolio positioning, hedging sector risk, or gaining quick liquidity. They can serve as “core” positions around which more active stock bets are layered. Because ETFs trade intraday and represent entire indexes, they’re ideal instruments for large managers needing instant exposure or rebalancing capability.
While most disclosures focus on U.S. equities, Citadel operates globally and trades foreign markets, fixed income, commodities, currencies, derivatives, etc. Public filings may not show all of these positions, especially in non-U.S. assets or private ventures abroad. So, his activity is likely even broader than what public U.S. stock filings reveal.
Citadel is known for active trading. Therefore, positions can shift dramatically quarter to quarter. Seasonal macro conditions, earnings, market sentiment, and strategies like volatility trading, arbitrage, or high frequency all drive rapid turnover. That’s why filings serve as snapshots, not real-time holdings.
Not in real time. Disclosures via 13F or 13D/G filings only appear quarterly and reflect positions at period end. Private investments are disclosed sporadically. For a near-complete picture, analysts must piece together filings, investor media, and press reports.
From the available information, Griffin’s investment style combines: