ALTAROCK PARTNERS LP — 13F-HR — 2026-06-30
U.S. SEC EDGAR · Published 17 Aug 2026 · Collected 22 Oct 2026
Original SEC XML preserved; count and dollar total reconciled; manager attribution retained · Original document retrieved
MMPHOTO PENDING
PERSON / P128INVESTOR
Mark Massey
Mark Massey is associated with AltaRock Partners in a July 2014 magazine interview listing. This historical evidence does not establish his current title or private holdings.
Biography: dorseyasset.com
READ THIS FIRST ↗
These are disclosures by an associated institution. The person’s name provides context; it does not establish current management, personal ownership or who made the trade.
A CLOSER LOOK / 30 Jun 2026Largest positions
Largest positions
in this source table.
Weights calculated from the complete reported table of U.S. SEC EDGAR. Denominator: that source’s disclosed public table, not personal wealth.
See source & scope ↗AMAZON.COM INC
32.21%
TRANSDIGM GROUP INC
27.51%
MICROSOFT CORP
20.54%
MASTERCARD INC-CLASS A
9.26%
VISA INC-CLASS A SHRS
Top 5 of 8 selected source-table records. 6.77%
Comparison unavailable.
Split adjustments and security identity require review before comparison.
01 / THE RECORDS8 MATCHING RECORDS
The disclosed positions.
2 record sources ↗| ASSET / SECURITY | REPORTED QUANTITY | REPORTED VALUE / USD | WEIGHT | QUARTERLY ACTIVITY | RECORD TYPE / OWNER | SOURCE |
|---|---|---|---|---|---|---|
| 023135106AMAZON.COM INC | 5,729,972shares | $1,365,681,526Reported market value$238.34 / reported unit (derived) | 32.21%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 893641100TRANSDIGM GROUP INC | 875,755shares | $1,166,540,690Reported market value$1,332.04 / reported unit (derived) | 27.51%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 594918104MICROSOFT CORP | 2,334,482shares | $870,808,476Reported market value$373.02 / reported unit (derived) | 20.54%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 57636Q104MASTERCARD INC-CLASS A | 764,507shares | $392,650,795Reported market value$513.6 / reported unit (derived) | 9.26%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 92826C839VISA INC-CLASS A SHRS | 836,470shares | $286,984,492Reported market value$343.09 / reported unit (derived) | 6.77%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 615369105MOODYS CORP | 302,624shares | $137,064,462Reported market value$452.92 / reported unit (derived) | 3.23%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 02079K305ALPHABET INC-CL A | 41,994shares | $15,007,396Reported market value$357.37 / reported unit (derived) | 0.35%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
| 43300A203HILTON WORLDWIDE | 15,202shares | $5,023,653Reported market value$330.46 / reported unit (derived) | 0.12%Share of this filing table | No comparable prior disclosure | Quarter-end positionAssociated institution30 Jun 2026 | U.S. SEC EDGAR ↗Record details ↗ |
Figures retain their source’s meaning. Unknown is not zero. Dates, share classes and option exposures may differ; source-table coverage is not a complete personal portfolio.
02 / THE REFERENCES
Go back to the evidence.
Details ↗Open in the source library ↗
ALTAROCK PARTNERS LP — 13F-HR — 2026-03-31
U.S. SEC EDGAR · Published 15 May 2026 · Collected 22 Oct 2026
Original SEC XML preserved; count and dollar total reconciled; manager attribution retained · Original document retrieved
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