Mark Massey
AltaRock Partners LP
AltaRock Partners runs an extremely concentrated portfolio built around a small number of very long-term, high-conviction ideas.
Portfolio as of March 31, 2026
| Company ↕ | Value ↓ | % ↕ | ||
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Quarterly moves
Q4 2025 → Q1 2026
Amount invested · % of portfolio
None
Amount bought · (±%) · % of portfolio
- AMAZON.COM INC $53M (+3.5%) · 38.2%
- MOODYS CORP $21M (+5.8%) · 9.1%
Amount sold · (±%) · % of portfolio
- TRANSDIGM GROUP INC $80M (-6.2%) · 25.5%
- MICROSOFT CORP $104M (-10.3%) · 16.8%
- MASTERCARD INC-CLASS A $11M (-3.5%) · 6.3%
- VISA INC-CLASS A SHRS $6M (-3.5%) · 3.7%
- ALPHABET INC-CL A $39M (-74.4%) · 0.3%
- HILTON WORLDWIDE $151M (-97.2%) · 0.1%
None
Portfolio value over time
Top 10 holdings evolution as of March 31, 2026
Share of portfolio (%) since inception, top 10 as of the selected quarter.
Sector breakdown
Based on holdings matched to a stock referenced on the site.
Dividend aristocrats held
Stocks with at least 25 consecutive years of dividend growth.
No matching holding among stocks referenced on the site.
Frequently asked questions
What are Mark Massey's top holdings?
As of March 31, 2026, the top three holdings of AltaRock Partners LP are AMAZON.COM INC, TRANSDIGM GROUP INC, MICROSOFT CORP.
How many positions does Mark Massey hold?
AltaRock Partners LP reports 8 equity positions worth $4.1B as of March 31, 2026.
Does Mark Massey invest in dividend stocks?
The weighted dividend yield of the covered portion of the portfolio is approximately 0.9%.
Data sourced from 13F filings submitted to the SEC, published with roughly 45 days of lag. A 13F only covers long positions in U.S.-traded securities: it excludes short sales, non-U.S. holdings and cash. Provided for informational purposes only and does not constitute investment advice.