ALTAROCK PARTNERS LP: TRANSDIGM GROUP INC (TDG): Quarterly 13F Position History
As of Q1 2026, ALTAROCK PARTNERS LP reported 909,168 shares of TRANSDIGM GROUP INC (TDG), worth $1.1B and representing 25.5% of its 13F equity book. Quarter-over-quarter share count change: 60,232 (-6.2%) . The position first appeared in Q1 2016 and has been disclosed across 41 13F-HR filings in Pactolio's tracked window.
- 909,168Shares Held (Latest Filing)
- $1.1BReported Market Value (Latest Filing)
- 25.5%Portfolio Weight (% of 13F Equity Book)
- 60,232Quarter-over-Quarter Share Change
- -$235.5MQuarter-over-Quarter Value Change
- 1,502,379Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 41 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 909,168 | 60,232 | -6.2% | $1.1B | 25.5% | $1159.0 |
| Q4 2025 | 969,400 | 6,992 | -0.7% | $1.3B | 25.3% | $1329.8 |
| Q3 2025 | 976,392 | 3,558 | -0.4% | $1.3B | 23.5% | $1318.0 |
| Q2 2025 | 979,950 | 0 | — | $1.5B | 27.2% | $1520.6 |
| Q1 2025 | 979,950 | 20,654 | -2.1% | $1.4B | 27.3% | $1383.3 |
| Q4 2024 | 1,000,604 | 47,660 | -4.5% | $1.3B | 25.7% | $1267.3 |
| Q3 2024 | 1,048,264 | 25,000 | -2.3% | $1.5B | 29.5% | $1427.1 |
| Q2 2024 | 1,073,264 | 83,134 | -7.2% | $1.4B | 28.2% | $1277.6 |
| Q1 2024 | 1,156,398 | 81,224 | -6.6% | $1.4B | 30.6% | $1231.6 |
| Q4 2023 | 1,237,622 | 72,464 | -5.5% | $1.3B | 27.9% | $1011.6 |
| Q3 2023 | 1,310,086 | 47,405 | -3.5% | $1.1B | 27.7% | $843.1 |
| Q2 2023 | 1,357,491 | 25,633 | -1.9% | $1.2B | 29.2% | $894.2 |
| Q1 2023 | 1,383,124 | 26,600 | -1.9% | $1.0B | 27.9% | $737.0 |
| Q4 2022 | 1,409,724 | 92,655 | -6.2% | $887.6M | 27.9% | $629.6 |
| Q3 2022 | 1,502,379 | +43,700 | +3.0% | $788.5M | 25.8% | $524.8 |
| Q2 2022 | 1,458,679 | +37,400 | +2.6% | $782.8M | 24.2% | $536.7 |
| Q1 2022 | 1,421,279 | +70,225 | +5.2% | $926.0M | 23.6% | $651.5 |
| Q4 2021 | 1,351,054 | +24,872 | +1.9% | $859.6M | 22.7% | $636.3 |
| Q3 2021 | 1,326,182 | +70,000 | +5.6% | $828.3M | 22.3% | $624.6 |
| Q2 2021 | 1,256,182 | +303,619 | +31.9% | $813.1M | 22.5% | $647.3 |
| Q1 2021 | 952,563 | 72,962 | -7.1% | $560.0M | 21.3% | $587.9 |
| Q4 2020 | 1,025,525 | 199,436 | -16.3% | $634.6M | 26.6% | $618.8 |
| Q3 2020 | 1,224,961 | +32,629 | +2.7% | $582.0M | 27.5% | $475.1 |
| Q2 2020 | 1,192,332 | +182,265 | +18.0% | $527.1M | 27.0% | $442.0 |
| Q1 2020 | 1,010,067 | +425,143 | +72.7% | $323.4M | 20.5% | $320.2 |
| Q4 2019 | 584,924 | 0 | — | $327.6M | 20.3% | $560.0 |
| Q3 2019 | 584,924 | 21,000 | -3.5% | $304.6M | 26.4% | $520.7 |
| Q2 2019 | 605,924 | 36,561 | -5.7% | $293.1M | 25.3% | $483.8 |
| Q1 2019 | 642,485 | 0 | — | $291.7M | 27.7% | $454.0 |
| Q4 2018 | 642,485 | +108,054 | +20.2% | $218.5M | 26.0% | $340.1 |
| Q3 2018 | 534,431 | 0 | — | $199.0M | 18.3% | $372.3 |
| Q2 2018 | 534,431 | 0 | — | $184.5M | 19.1% | $345.1 |
| Q1 2018 | 534,431 | 45,100 | -7.8% | $164.0M | 18.8% | $306.9 |
| Q4 2017 | 579,531 | 67,000 | -10.4% | $159.2M | 20.9% | $274.6 |
| Q3 2017 | 646,531 | +74,367 | +13.0% | $165.3M | 24.2% | $255.7 |
| Q2 2017 | 572,164 | +36,094 | +6.7% | $153.8M | 21.7% | $268.9 |
| Q1 2017 | 536,070 | 55,434 | -9.4% | $118.0M | 17.5% | $220.2 |
| Q4 2016 | 591,504 | +152,356 | +34.7% | $147.3M | 21.6% | $249.0 |
| Q3 2016 | 439,148 | 0 | — | $127.0M | 20.2% | $289.1 |
| Q2 2016 | 439,148 | 291,067 | -39.9% | $115.8M | 21.0% | $263.7 |
| Q1 2016 | 730,215 | — | — | $160.9M | 29.7% | $220.3 |
Methodology & FAQ
How This Position History Is Sourced
Each row is one SEC Form 13F-HR filing disclosing this position. Share count, market value, and reported quarter are taken verbatim from the filing; portfolio weight is recomputed against the same filing's total reported equity book. Implied price-per-share is market value divided by shares — a quarter-end mark, not the manager's cost basis. See the full methodology document for the normalization rules.
When did ALTAROCK PARTNERS LP first disclose a TDG position in 13F-HR filings?
ALTAROCK PARTNERS LP first reported TRANSDIGM GROUP INC (TDG) on its 13F-HR filing for the period ending 2016-03-31 (Q1 2016). The position has appeared on 41 reported quarters within Pactolio's tracked window.
What was ALTAROCK PARTNERS LP's most recent quarter-over-quarter share-count change in TDG?
Between Q4 2025 and Q1 2026, ALTAROCK PARTNERS LP reduced its TDG position by 60,232 shares (-6.2%), leaving 909,168 shares at a market value of $1.1B.
Does the implied price-per-share represent ALTAROCK PARTNERS LP's cost basis in TDG?
No. The implied price-per-share column is the 13F-HR reported market value divided by reported share count on the filing date (end of quarter). It is a quarter-end mark, not a cost basis or transaction price. Use it as a sanity check on the value column, not as an indicator of the manager's entry or exit price.