Broad Run 13F (2026 Q1): A 24-Stock Book, One 21% Bet

What real concentration looks like

Most managers who call themselves concentrated hold 30 or 40 names. Broad Run Investment Management means it: its 2026Q1 13F lists just 24 positions, and a single holding accounts for more than a fifth of the entire book. The firm, run by a team that previously managed a well-known focused growth fund, practices genuinely high-conviction, long-horizon investing, the kind where a handful of decisions determine the outcome. Its roughly $568 million portfolio is a vivid case study in what extreme concentration actually looks like in a filing.

The dominant position is AST SpaceMobile at 21.35% of reported value, an extraordinary weight for a single stock. AST is an ambitious, still-early satellite company aiming to deliver mobile broadband directly to ordinary phones from space, a high-risk, high-reward bet whose outcome will swing this portfolio more than any other holding. Sizing one speculative name at over 20% is a statement of conviction that few managers would make, and it defines the risk profile of the entire book.

Quality compounders fill out the rest

Behind that outsized bet, the portfolio looks more like a classic quality-growth book. Applied Materials (8.93%), Brookfield (8.63%), and Brookfield Asset Management appear alongside Markel, O'Reilly Automotive, Aon, Hilton, and American Tower, a roster of high-quality compounders with durable economics. The combination is distinctive: a foundation of proven, cash-generative franchises paired with one large, speculative growth bet. That pairing, durable quality plus a single asymmetric wager, is a recognizable signature of conviction-driven concentrated managers.

The quarter's moves

Reported value rose 5.5% on the quarter to about $568 million and has held in a narrow band over the past two years. The activity was characteristically light for a low-turnover manager: a new position in Sunbelt Rentals at nearly 8% of the book, a 50% increase in Brookfield Asset Management, and small trims to AST SpaceMobile, Applied Materials, and O'Reilly. Notably, even after trimming slightly, the firm left AST as a fifth of the portfolio, a sign it remains committed to the thesis rather than quietly reducing risk. Adding a new name at 8% in a 24-stock book is itself a high-conviction act, the kind of decisive sizing that defines this style.

How to read an extremely concentrated book

A filing like Broad Run's demands a different risk lens than a diversified one. When one position is over 20% of the book, the portfolio's fate is tied disproportionately to that single company, so understanding the largest holding is not optional, it is the whole analysis. The upside of such concentration is that being right on a few names can drive exceptional returns; the downside is that a single thesis breaking can dominate the result, with little diversification to cushion it. For investors who follow concentrated managers for ideas, the key is to evaluate the big position on its own merits and to recognize that you are looking at conviction expressed without a safety net. You can explore the full 24-position book, the quarter-over-quarter changes, and the longer history on the Broad Run filer page.