Altarock Partners Lp
- Regulatory AUM
- $5.7B
- Discretionary
- $5.7B
- Clients
- 2
- Avg AUM / client
- $2.8B
- Accounts
- 2
- Employees
- 7
AUM over time
Annual snapshots from Form ADV filings · as of Apr 24, 2026
Investments (13F portfolio — 8 positions, $4,126,337,614)
13F period Mar 31, 2026| # | Issuer | Class | Value | Shares | % of 13F | % of AUM |
|---|---|---|---|---|---|---|
| 1 | Amazon.Com Inc | COMM | $1,576,176,113 | 7,567,946 | 38.2% | 27.8% |
| 2 | Transdigm Group Inc | COMM | $1,053,689,345 | 909,168 | 25.5% | 18.6% |
| 3 | Microsoft Corp | COMM | $691,306,171 | 1,867,537 | 16.8% | 12.2% |
| 4 | Moodys Corp | COMM | $376,063,205 | 862,036 | 9.11% | 6.64% |
| 5 | Mastercard Inc Class A | COMM | $261,240,236 | 522,836 | 6.33% | 4.61% |
| 6 | Visa Inc Class A Shrs | COMM | $150,720,137 | 498,677 | 3.65% | 2.66% |
| 7 | Alphabet Inc Cl A | COMM | $12,477,516 | 43,391 | 0.3% | 0.22% |
| 8 | Hilton Worldwide | COMM | $4,664,891 | 15,341 | 0.11% | 0.08% |
Top 25 of 8 positions from the manager's latest Form 13F · source filing (EDGAR) ↗. 13F covers long US-listed positions only. "% of AUM" is share of the firm's total regulatory AUM (Form ADV Item 5.F).
Who they serve
| Client type | Clients | AUM | % of AUM |
|---|---|---|---|
| Pooled investment vehicles (non-investment companies) | 2 | $5.7B | 100.0% |
Private funds (2)
Reported in Form ADV Section 7.B.(1), filing of Aug 2024 · $4.6B combined gross assets
| Fund | Type | Domicile | Gross assets | Owners |
|---|---|---|---|---|
| Bbh Altarock Partners Master Fund, Lp master | Hedge Fund | Cayman Islands | $2.6B | 1,850 |
| Altarock Fund, Lp | Hedge Fund | Delaware | $2.1B | 97 |
People (2)
| Name | Role / title | Credentials | With firm since | Ownership |
|---|---|---|---|---|
| Massey, Mark, Thomas | Chief Executive Officer | Feb 2002 (25y) | 75% or more | |
| Cabot, Shannon, Theriault | Chief Compliance Officer | Sep 2014 (12y) | Less than 5% |
Entity owners (Schedule A/B)
| Entity | Title / status | Since | Sch. | Ownership |
|---|---|---|---|---|
| Big Mound Partners, Llc | General Partner | Jan 2024 | A | Less than 5% |
Undisclosed: 0% – 25% of the firm is not attributable from the filed Schedule A bands.
Roster from the IAPD representatives feed; ownership and acquisition dates from Form ADV Schedule A/B. "Since" is the earliest filed registration or acquisition date.
Private funds (2, $4.6B gross assets)
| Fund | Type | Gross assets | Min. investment | Owners |
|---|---|---|---|---|
| Bbh Altarock Partners Master Fund, Lp | Hedge Fund | $2.6B | $100K | 1,850 |
| Altarock Fund, Lp | Hedge Fund | $2.1B | $5.0M | 97 |
From Form ADV Section 7.B private fund reporting.
Documents (1 archived)
| Form | Period | Size | |
|---|---|---|---|
| Form ADV (full filing) | 04/24/2026 | 1.38 MB | View · PDF · Source ↗ |
Archived copies of the firm's regulatory filings, versioned by content hash.
Disciplinary disclosures
No disciplinary events reported on the firm's latest Form ADV filing.
How they charge
- • Percentage of assets under management
- • Performance-based fees
Services
- • Portfolio management for pooled investment vehicles
Custody
Firm reports it does not have custody of client funds or securities (Item 9.A).
No custodian data reported or mined yet.
Source
All data on this page comes from this firm's Form ADV filings, reproduced without modification. Latest filing: Apr 24, 2026.
View current Form ADV (SEC/IAPD) ↗