You won't find a flashy website for Baker Bros. Advisors. No "About Us" page with stock photos of smiling scientists. No "Insights" blog or Twitter account posting hot takes on the federal interest rate. Most people in the finance world know Julian Baker and his brother Felix as the quietest titans in the room. They don't want the spotlight. Honestly, they seem to actively run away from it.
Yet, when Julian Baker baker brothers pops up in SEC filings, the smart money stops and stares. These guys are the "Superinvestors of Life Sciences." They aren’t just playing the market; they’re often the ones sitting in the boardroom helping build the companies that eventually save lives. In a world of high-frequency trading and 24-hour news cycles, the Baker brothers are doing something that feels almost ancient: they're waiting.
The Mystery of Julian Baker and the Baker Brothers
So, who are they? Julian Baker got his start in the private equity arm of Credit Suisse First Boston back in the late 80s. His brother, Felix, is the "science guy" with a Ph.D. in immunology from Stanford. They eventually teamed up to manage money for the legendary Tisch family (the folks behind Loews Corp). By 2000, they went off on their own.
They focus almost exclusively on biotechnology. It's a brutal sector. Most drugs fail. Most companies go bust before they even reach a Phase 3 trial. But the Bakers have a track record that makes the S&P 500 look like a savings account.
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Why the Seagen Deal Changed Everything
If you want to understand the scale of their success, you have to look at Seagen (formerly Seattle Genetics). Most investors jump in and out of stocks like they're playing a game of hot potato. Not the Baker brothers. They held Seagen for two decades.
- The Windfall: In 2023, Pfizer bought Seagen for $43 billion.
- The Stake: Baker Bros. Advisors held roughly 25% of the company at various points.
- The Result: A windfall gain estimated at over $8 billion.
Think about that. They didn't just pick a winner; they nursed it for 20 years. When the deal closed, they actually returned a massive chunk of that cash to their investors—primarily endowments and foundations—because they didn't think they could deploy it all at once without compromising their standards. That kind of discipline is basically unheard of in the hedge fund world.
How Julian Baker and Felix Baker Actually Invest
They don't just "buy" stocks. They take "active positions." This means Julian or Felix (or one of their trusted deputies) often sits on the board of directors. They aren't just watching the ticker; they are helping decide which clinical trials to fund and which CEOs to hire.
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As of early 2026, their portfolio remains heavily concentrated. They don't believe in diversification for the sake of it. If they like a company, they go all in.
The Current Big Bets
Looking at recent filings from late 2025 and early 2026, their top holdings tell a story of high-conviction science:
- Incyte Corporation (INCY): A long-term staple. Julian has been on the board here since the early 2000s.
- BeOne Medicines (ONC): A massive position that has seen significant movement recently.
- Madrigal Pharmaceuticals (MDGL): They've been backing Madrigal’s work in liver disease for years.
- Acadia Pharmaceuticals (ACAD): Another core pillar of their long-term strategy.
They also have significant stakes in places like Kymera Therapeutics and Kodiak Sciences. They aren't looking for a 10% gain over six months. They are looking for the next breakthrough in oncology or rare diseases that will redefine a market.
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The "Secret Sauce" Nobody Talks About
People always ask what the "trick" is. Kinda funny, because it's not a trick. It's rigor.
When they evaluate a company, they don't just look at the balance sheet. They bring in a team of 8 or 10 experts—real scientists—to tear apart the data. They look at the immunology, the molecular biology, and the clinical trial design. If the science isn't perfect, they walk.
And they are loyal. One biotech CEO mentioned in an interview that during a rough patch, the Baker brothers told him, "You fix the price to whatever you think is right." They aren't trying to squeeze pennies out of the founders. They want the company to survive long enough to get the drug to market.
Common Misconceptions
- "They are just lucky": You don't stay at the top for 25 years in biotech on luck.
- "They only do big pharma": Nope. They love early-stage discovery. They just have the patience to wait for that discovery to mature.
- "They are aggressive": While they take big stakes, they are known for being collaborative board members, not "vulture" activists.
What You Can Learn from Julian Baker Baker Brothers
You probably don't have $20 billion to play with, and you definitely don't have a team of Ph.D.s. But the Julian Baker baker brothers philosophy is actually pretty applicable to regular people.
- Stop Day Trading: If the Bakers can wait 20 years for Seagen, you can wait more than 20 minutes for your tech stock to move.
- Focus on Quality, Not Quantity: They only hold about 30-90 stocks at a time, with the vast majority of their money in the top 10.
- Do the Work: Don't buy a biotech stock because a guy on Reddit said it's a "moon mission." Understand the product. If you can't explain what the drug does, don't buy the stock.
The biotechnology sector in 2026 is faster and more complex than ever. With AI-driven drug discovery and new gene therapies hitting the market, the noise is deafening. Julian Baker and the Baker brothers show us that the best way to win isn't to shout louder—it's to be the quietest person in the room with the best data.
Actionable Next Steps
- Track the 13F Filings: Since the Baker brothers have no website, the only way to see what they are doing is to watch their SEC Form 13F filings. These are released quarterly and show exactly what they bought and sold.
- Watch the Board Seats: Pay attention to which companies Julian Baker or Felix Baker join as directors. This usually signals a deep, multi-year commitment to the company's success.
- Monitor the M&A Landscape: As big pharma companies (like Pfizer or Merck) look to replenish their pipelines, they often look at "Baker-backed" companies first because they know the scientific due diligence has already been done by the best in the business.