Baupost Group Adds Aon, Boosts Amazon in Q1 Filing

Seth Klarman’s Baupost Group revealed significant portfolio adjustments in its first-quarter 2026 13F filing, which was made public on May 14, 2026. The Boston-based hedge fund, known for its disciplined value investing approach, initiated a new position in professional services firm Aon plc. The filing also showed Baupost increased its already substantial holding in Amazon while completely exiting its stake in building materials company CRH plc. The new Aon stake was valued at approximately $350 million as of the filing date.

What New Positions Did Baupost Initiate?

The most prominent new addition to Baupost's portfolio was Aon plc (AON), a global professional services firm providing risk, retirement, and health solutions. The fund acquired over 1.1 million shares, establishing a position valued at roughly $350 million. This move represents a significant allocation for a new holding and aligns with Klarman’s strategy of investing in established companies with durable business models.

Aon operates in a sector with high barriers to entry and consistent demand, characteristics often favored by value investors. The company's performance is tied to global economic activity and corporate spending on insurance and consulting services. This investment suggests Baupost sees long-term value in the insurance brokerage and professional services industry, potentially at a price that offered a sufficient margin of safety.

Why Did Baupost Increase Its Amazon Stake?

Baupost also bolstered its conviction in Amazon (AMZN), adding approximately 1.2 million shares to its position. This purchase increased the fund's total holding in the tech giant to over 8 million shares, with a market value exceeding $1.5 billion at the end of the first quarter. The move reinforces Amazon’s status as one of Baupost’s largest public equity holdings.

The decision to buy more Amazon stock indicates that Klarman’s team continues to see upside, even with the company's trillion-dollar market capitalization. The thesis may be centered on the sustained growth of Amazon Web Services (AWS), its cloud computing division, which generates substantial high-margin revenue. Further potential in its advertising business and a recovery in e-commerce growth could also be contributing factors to the fund's bullish stance on tech stocks.

Which Major Holding Did Klarman Exit?

In a notable liquidation, Baupost sold its entire stake in CRH plc (CRH), an Ireland-based global leader in building materials. The position, which consisted of over 5 million shares, was valued at approximately $415 million at the end of the previous quarter, Q4 2025. Completely exiting a holding of this size signals a definitive change in the fund's outlook for the company or the sector.

The sale could be attributed to several factors. Baupost may have decided to take profits after a period of strong performance for the stock. Alternatively, the fund may have developed concerns about the outlook for the global construction and infrastructure markets amid shifting economic conditions. This capital was likely reallocated to new opportunities like Aon, where the fund identified a more attractive risk-reward profile.

How Do These Trades Reflect Baupost's Strategy?

These first-quarter trades are consistent with Seth Klarman's investment philosophy, detailed in his 1991 book, "Margin of Safety." The fund actively rebalances its portfolio by trimming or exiting positions that have met their price targets and initiating new ones in undervalued assets. The rotation from CRH into Aon exemplifies this discipline, shifting capital from a cyclical industrial to a stable professional services firm.

A key limitation of analyzing 13F filings is their backward-looking nature. The data reflects positions held as of March 31, 2026, and offers no insight into short positions, cash levels, or non-U.S. equities. Baupost's portfolio could have changed significantly in the 45 days between the end of the quarter and the filing date. Therefore, the filing is a snapshot, not a real-time representation of the fund's holdings.

Q: What is a 13F filing?

A: A 13F is a quarterly report mandated by the U.S. Securities and Exchange Commission (SEC) for institutional investment managers with at least $100 million in equity assets under management. The report discloses their long positions in U.S. exchange-listed securities, providing a partial view of their portfolio. It is due within 45 days of the end of each calendar quarter.

Q: Does Baupost Group invest only in public equities?

A: No, the 13F filing represents only a fraction of Baupost's overall strategy. The fund is known for its flexible mandate, investing across a wide range of asset classes including distressed debt, real estate, private equity, and other credit instruments. Its public equity holdings are just one component of a much broader and more complex investment portfolio.

Q: How large is Baupost Group?

A: While as a private entity it does not disclose exact figures regularly, Baupost Group is one of the largest hedge funds in the world. As of early 2026, its assets under management (AUM) were estimated to be approximately $27 billion. The firm has a long track record of delivering strong returns for its clients since its founding in 1982.

Bottom Line

Baupost's Q1 filing signals a classic value rotation, favoring professional services and mega-cap technology over the building materials sector.

Disclaimer: This article is for informational purposes only and does not constitute investment advice. CFD trading carries high risk of capital loss.