Breaking down the stocks Mark Massey and Scott Bradford (AltaRock Partners) bought, sold, and held in Q4 2025, including their holdings at the end of the quarter. All data sourced from AltaRock Partners' 13F filed on February 13, 2026.
Who are Mark Massey, Scott Bradford and AltaRock Partners?
AltaRock Partners is a highly concentrated investment firm founded by Mark Massey and Scott Bradford, both Harvard MBA graduates with distinguished investment backgrounds. Massey previously worked at Seth Klarman's Baupost Group, while Bradford gained experience at Fiduciary Management Associates. The firm maintains an extremely focused portfolio typically comprising fewer than ten holdings with a combined value of approximately $4.8 billion. AltaRock's investment philosophy centers on identifying exceptional businesses with durable competitive advantages and holding them for the long term.
Altarockpartners.com
Q4 '25 13F filed with SEC
Holdings in Q4 2025
| Ticker | Company | Weight | Change | Value |
|---|---|---|---|---|
| AMZN | Amazon | 33.1% | Trimmed (-3%) | $1.69B |
| TDG | TransDigm | 25.3% | Trimmed (-1%) | $1.29B |
| MSFT | Microsoft | 19.7% | Trimmed (-19%) | $1.01B |
| MCO | Moody's | 8.2% | Trimmed (-14%) | $416.09M |
| MA | Mastercard | 6.1% | Trimmed (-7%) | $309.32M |
| V | Visa | 3.6% | Trimmed (-3%) | $181.2M |
| HLT | Hilton | 3.1% | $155.87M | |
| GOOGL | Alphabet | 1.0% | Trimmed (-51%) | $53.02M |
| FICO | Fair Isaac | 0.0% | Exited | $-998.19K |
Current Investment Strategy
Mark Massey and Scott Bradford's AltaRock Partners continued to run an ultra-concentrated, low-turnover portfolio of wide-moat compounders in Q4 2025, anchored by dominant positions in Amazon, Microsoft, and TransDigm alongside durable franchises in payments (Mastercard, Visa), credit ratings (Moody's), and hospitality (Hilton), while exiting its stake in Fair Isaac. The Baupost Group alumni's Buffett-inspired approach—treating fewer than ten holdings as permanent ownership stakes in businesses with sustainable competitive advantages—yielded minimal portfolio activity during the quarter, reflecting the firm's conviction that patient capital deployed in asset-light, free-cash-flow-rich enterprises will compound over decades.
New Investments
AltaRock Partners did not open any new positions during Q4 2025.
Added, Trimmed, and Exited
Added
AltaRock Partners made no additions to any existing positions this quarter.
Trimmed
AltaRock Partners trimmed across nearly every holding in Q4 2025. The most significant reduction was in Microsoft (MSFT), where the firm sold roughly 487,000 shares (~19% of the position), followed by a ~244,000-share trim in Amazon (AMZN) and a substantial ~51% cut to Alphabet (GOOGL) (~175,000 shares). The firm also reduced Moody's (MCO) by ~134,000 shares (~14%), Mastercard (MA) by ~42,000 shares (~7%), Visa (V) by ~17,000 shares (~3%), and TransDigm (TDG) by a modest ~7,000 shares (~1%).
What it means: The sweeping trims across virtually the entire portfolio suggest AltaRock is deliberately harvesting gains and raising cash rather than rotating into new ideas. The deepest cuts came in large-cap tech — particularly Alphabet (GOOGL) and Microsoft (MSFT) — which may reflect concerns about stretched valuations or slowing growth prospects in those names. The lighter trims to compounders like TransDigm (TDG) and Visa (V) indicate the firm still has higher conviction there. For a highly concentrated fund that typically holds fewer than ten positions, this broad-based selling without any new additions is notable and could signal a more cautious outlook heading into 2026.
Exited
AltaRock Partners fully liquidated its small position in Fair Isaac (FICO), selling all 667 shares valued at roughly $1 million.
What it means: The Fair Isaac (FICO) position was tiny relative to AltaRock's ~$4.8 billion portfolio, suggesting it may have been a residual or exploratory stake rather than a core conviction holding. Its exit is consistent with the firm's broader trimming theme this quarter and its preference for maintaining an ultra-concentrated portfolio.
Disclaimer: All posts are for informational purposes only. They are NOT a recommendation to buy or sell the securities discussed. Please do your own research and due diligence before investing your money.
