Legendary billionaire Ken Griffin makes huge bet on major tech stock | Official Website of Louis Velazquez, entrepreneur, finance guy and tech innovator

Ken Griffin usually doesn’t make headlines with a solitary trade, but his latest move into Meta Platforms (META) is the kind that compels Mr.Market to sit up straight.

The Citadel founder, known for precision position-sizing along with a healthy dose of skepticism toward hype cycles, went from not being involved in the stock at all to making Meta one of his biggest tech positions in just one quarter.

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That pivot usually doesn’t happen by chance, but when a legendary investor decides a company is entering a new chapter in its growth story, and he’s looking to get in early.

Perhaps what makes his buy even more stunning is that Griffin openly warned about “echoes of the dot-com bubble” in today’s AI market.

Yet when there was an opportunity, he didn’t run from Big Tech; he basically ran toward Meta.

Citadel’s billionaire founder quietly rewired part of his portfolio

Photo by Kayla Bartkowski on Getty Images

Ken Griffin’s legacy and investing philosophy

Griffin’s moves matter because hardly any investors have built such an enviable track record as his.

Fund manager buys and sells

He started trading from his Harvard dorm room back in the late 1980s, even installing a satellite dish on the roof to receive real-time quotes.

In 1990, he launched Citadel with just $4.6 million. Thirty-five years later, that fledgling startup evolved into a multi-strategy powerhouse managing north of $65 billion in assets, known for its quantitative firepower, world-class talent, and progressive culture.

Griffin’s investing philosophy is simple in that it’s imperative to “Know your edge… if I can’t establish what our competitive advantage is going to be, there’s no point starting the journey.”

That discipline paid off immensely.

Citadel generated nearly $74 billion in cumulative net profits, the most of any hedge fund in history. In 2022 alone, it posted a mind-boggling 38% return, along with a record $16 billion gain for investors.

Currently, his portfolio is worth a jaw-dropping $608 billion.

Griffin’s Meta bet sends a clear message

Ken Griffin’s Meta buy felt like a declaration.

Citadel boosted its Meta stake by a stellar 12,693% in Q3 2025, going from virtually zero exposure to a hefty1.96 million shares worth about $1.44 billion.

For a firm that’s known for risk discipline, multiplying a position over 126-fold in just one quarter is basically close to Griffin getting to shouting.

Meta has become a full-fledged AI powerhouse, and the robust combo of AI-enhanced advertising, stronger content recommendations, such as Instagram Reels, and the successful open-sourcing of its Llama model ecosystem.

Consequently, it has been killing it on the fundamentals, with Meta posting a record Q3 2025 sales of $51.2 billion (up 26% year-over-year) with generative AI bumping up ad demand.

Hence, Meta’s potent strategy positions it as perhaps a core “AI economy” player, offering a stronger near-term payoff than most Mag 7 peers. For Griffin, that’s not hype, that’s an opportunity worth betting a billion dollars on.

Griffin rebuilds tech portfolio around AI core

Before going all-in on Griffin’s specific trades, it’s important to note the backdrop he’s operating in.

The market’s AI surge has been led by a handful of tech giants, known as the “Magnificent 7.”

Since late 2022, these businesses have driven 75% of the S&P 500’s returns, while accounting for 80% of its earnings growth, according to J.P. Morgan’s research.

Also, these names make up almost 37% of the entire benchmark index. Their level of AI spending, from chips to cloud to LLMs, has effectively reshaped the market.

The Magnificent 7 (with tickers)

Apple (AAPL) – iPhone-maker that continues to lean heavily into on-device AI and ecosystem upgrades.
Microsoft (MSFT) – Cloud giant and OpenAI backer that continues to drive enterprise AI adoption.
Alphabet (GOOGL) – Search, cloud, Gemini models, along with a colossal AI infrastructure spend, make it a titan like none other.
Amazon (AMZN) – AWS continues to fuel AI workloads while training demand across sectors.
Meta Platforms (META) – Llama models, AI-driven ads, and soaring Reels recommendations have fueled a comeback.
Nvidia (NVDA) – The GPU engine behind the entire AI boom.
Tesla (TSLA) – Autonomy, Dojo, and AI-driven manufacturing promises are pushing the EV giant ahead.

What Griffin bought, trimmed, and avoided

Once we glance at Citadel’s full Q3 trades, Griffin’s broader strategy seems virtually impossible to ignore.

It wasn’t random tinkering, and more of a coordinated reshaping of perhaps the most sophisticated portfolios built around companies he feels will define the next decade of AI.

What he bought (aggressively)

Meta Platforms: Increased by 12,693% to 1.96 million shares (about $1.44 billion).
Microsoft: Doubled his stake to nearly 3.97 million shares.
Apple: Raised its stake by 108% to about 4.92 million shares.
Alphabet (two classes): Increased one class by 200% and the other by 268%.
Tesla: Roughly quadrupled its position, up 280%, to approximately 1.5 million shares.
Nvidia: Added another 21%, bringing the total to roughly 9.8 million shares.

What he trimmed

Amazon: Reduced the position by 39%, currently holding about 3.24 million shares.