AltaRock Partners portfolio & holdings
AltaRock Partners
Historical clone performance and limitations
AltaRock Partners (AltaRock Partners) discloses a $4.24B portfolio across 8 US-listed positions in the latest 13F filing (2026Q2, filed Aug 17, 2026). The largest holding is AMZN at 32.2% of the book.
A material reported change · Q2 2026
AltaRock Partners reduced reported AMZN shares by 24.3%.
Holdings as of Jun 30, 2026 · filed Aug 17, 2026. Position at period end: 32.2% of the reported portfolio. The filing does not reveal the trade date, price, or reason.
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Holdings (8) · click any column to sort
| #↑ | Ticker | Issuer | % Port. | This Q | History | Value |
|---|---|---|---|---|---|---|
| 1 | AMZN | 32.2% | $1.37B | |||
| 2 | TDG | 27.5% | $1.17B | |||
| 3 | MSFT | 20.5% | $871M | |||
| 4 | MA | 9.3% | $393M | |||
| 5 | V | 6.8% | $287M | |||
| 6 | MCO | 3.2% | $137M | |||
| 7 | GOOGL | 0.4% | $15M | |||
| 8 | HLT | 0.1% | $5M |
- 1AMZNport32.2%val$1.37BAmazon.com Incthis Q -24%·18q
- 2TDGport27.5%val$1.17BTransdigm Group Incthis Q hold·40q
- 3MSFTport20.5%val$871MMicrosoft Corpthis Q +25%·21q
- 4MAport9.3%val$393MMastercard Inc - Athis Q +46%·40q
- 5Vport6.8%val$287MVisa Inc-class A Sharesthis Q +68%·40q
- 6MCOport3.2%val$137MMoody's Corpthis Q -65%·40q
- port0.4%val$15MAlphabet Inc-cl Athis Q hold·27q
- 8HLTport0.1%val$5MHilton Worldwide Holdings INthis Q hold·7q
2026Q2 moves, by size (5)(expand ↓)
| Ticker | Issuer | Move | % Port. | Δ Shares | Value |
|---|---|---|---|---|---|
| AMZN | Amazon.com Inc | TRIM | 32.2% | -24% | $1.37B |
| MSFT | Microsoft Corp | ADD | 20.5% | +25% | $871M |
| MA | Mastercard Inc - A | ADD | 9.3% | +46% | $393M |
| MCO | Moody's Corp | TRIM | 3.2% | -65% | $137M |
| V | Visa Inc-class A Shares | ADD | 6.8% | +68% | $287M |
- TRIMAMZN32.2%Amazon.com IncΔ -24%·$1.37B
- ADDMSFT20.5%Microsoft CorpΔ +25%·$871M
- ADDMA9.3%Mastercard Inc - AΔ +46%·$393M
- TRIMMCO3.2%Moody's CorpΔ -65%·$137M
- ADDV6.8%Visa Inc-class A SharesΔ +68%·$287M
About AltaRock Partners
AltaRock Partners is a Boston-based concentrated long-only equity manager founded by Jim Goetz and John Melas-Kyriazi, running what amounts to a high-conviction compounding portfolio: eight disclosed positions at last count, with the top five accounting for roughly 96% of a $4.1B book. The style sits in the Munger-influenced "wonderful businesses at fair prices" tradition — Amazon, TransDigm, Microsoft, Moody's, and Mastercard have been persistent core holdings, each chosen for durable pricing power and reinvestment runway. There are no known short positions, options overlays, or derivatives strategies that would create material divergence between the 13F and the actual portfolio; what you see is largely what they own. The 45-day disclosure lag is the primary friction for anyone attempting to clone the book — position-level changes can be meaningful given how few names are held, so a quarterly filing may already reflect a full turn in one of the top weights.
2026Q2 brief
AltaRock's hyper-concentrated $4.2B, 8-position book made its most visible shift by aggressively building V (+68%, now 6.8%) and MA (+46%, 9.3%) while simultaneously cutting MCO by nearly two-thirds (-65%, down to 3.2%) and trimming AMZN (-24%, still the top holding at 32.2%). The net effect is a tilt further into payment network duopoly — combined V and MA now represent over 16% — at the partial expense of the financial data/analytics exposure that MCO provided. MSFT was added 25% to reach 20.5%, cementing the top-three as AMZN/TDG/MSFT at a combined 80% of AUM, an extraordinary concentration even by AltaRock's standards. The MCO trim is notable because it diverges from peers like Akre and Nygren who remain committed to Moody's. Watch whether TDG (27.5%) sees any trimming next quarter as aerospace aftermarket valuations stretch, and whether the HLT stub (0.1%) gets built into a real position.
AI-generated. Not investment advice.
Filing history
AltaRock Partners's disclosed 13F portfolio value and position count by quarter — the trajectory across every SEC filing.
| Quarter | Positions | Portfolio value |
|---|---|---|
| Q2 2026 — what changed → | 8 | $4.24B |
| Q1 2026 — what changed → | 8 | $4.13B |
| Q4 2025 — what changed → | 8 | $5.10B |
| Q3 2025 — what changed → | 9 | $5.47B |
| Q2 2025 — what changed → | 9 | $5.48B |
| Q1 2025 — what changed → | 9 | $4.97B |
| Q4 2024 holdings | 10 | $4.94B |
| Q3 2024 holdings | 9 | $5.08B |
| Q2 2024 holdings | 9 | $4.86B |
| Q1 2024 holdings | 8 | $4.65B |
| Q4 2023 holdings | 8 | $4.48B |
| Q3 2023 holdings | 8 | $3.99B |
Values as disclosed at each quarter end. Older filings on EDGAR.
Manager evidence
17 material decisions, preserved in sequence.
See what AltaRock Partners bought, added, trimmed, or exited across eight quarters—plus disclosure lag, SEC sources, and observed outcomes versus SPY. No guru grade.
Open AltaRock Partners's decision evidence →Frequently asked questions
- What stocks does AltaRock Partners own?
- As of 2026Q2, AltaRock Partners's 13F discloses 8 positions worth $4.24B. The top five holdings: AMZN (32.2%), TDG (27.5%), MSFT (20.5%), MA (9.3%), V (6.8%). 13F filings cover long US-listed equities only — cash, bonds, shorts, and non-US positions are not disclosed.
- What did AltaRock Partners buy this quarter?
- In 2026Q2, the filing shows 0 new positions and 3 additions to existing holdings. The largest positions touched by buying: MSFT, MA, V.
- How big is AltaRock Partners's portfolio?
- $4.24B across 8 positions per the latest 13F (filed Aug 17, 2026). The top five holdings account for 96% of the disclosed book.
Similar portfolios
Long US equity 13F-HR filings only — no shorts, no derivatives. SEC filings at EDGAR (CIK 0001631014). Not investment advice.