TransDigm Group Incorporated
MX ˙ BMV ˙ US8936411003
SecurityMX:TDG / TransDigm Group Incorporated
InstitutionBlair William & Co/il
Latest Disclosed Ownership166,248 shares
Latest Disclosed Value $ 192,675,350
Blair William & Co/il ownership in TDG / TransDigm Group Incorporated

On May 8, 2026 - Blair William & Co/il filed a 13F-HR form disclosing ownership of 166,248 shares of TransDigm Group Incorporated (MX:TDG) valued at $192,675,350 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 170,230 shares of TransDigm Group Incorporated. This represents a change in shares of -2.34% during the quarter.

Blair William & Co/il has a history of taking positions in derivatives of the underlying security (TDG) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:TDG / TransDigm Group Incorporated Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-08 2026-03-31 13F TRANSDIGM GROUP COM 893641100 166,248 -3,982 -2.34 192,675 -14.89 0.5521
2026-02-17 2025-12-31 13F TRANSDIGM GROUP COM 893641100 170,230 -2,419 -1.40 226,381 -0.52 0.6076
2025-11-12 2025-09-30 13F TRANSDIGM GROUP COM 893641100 172,649 -304 -0.18 227,555 -13.48 0.6057
2025-07-24 2025-06-30 13F TRANSDIGM GROUP COM 893641100 172,953 -2,268 -1.29 263,000 8.51 0.7305
2025-05-09 2025-03-31 13F TRANSDIGM GROUP COM 893641100 175,221 -3,122 -1.75 242,382 7.24 0.7310
2025-02-12 2024-12-31 13F TRANSDIGM GROUP COM 893641100 178,343 674 0.38 226,011 -10.86 0.6574
2024-11-12 2024-09-30 13F TRANSDIGM GROUP COM 893641100 177,669 285 0.16 253,557 11.88 0.7447
2024-08-12 2024-06-30 13F TRANSDIGM GROUP COM 893641100 177,384 188 0.11 226,628 3.85 0.6990
2024-05-09 2024-03-31 13F TRANSDIGM GROUP COM 893641100 177,196 4,213 2.44 218,235 24.71 0.6854
2024-02-12 2023-12-31 13F TRANSDIGM GROUP COM 893641100 172,983 477 0.28 174,990 20.31 0.5963
2023-11-09 2023-09-30 13F TRANSDIGM GROUP COM 893641100 172,506 1,940 1.14 145,445 -4.64 0.5578
2023-08-11 2023-06-30 13F TRANSDIGM GROUP COM 893641100 170,566 -448 -0.26 152,515 21.00 0.5587
2023-05-12 2023-03-31 13F TRANSDIGM GROUP COM 893641100 171,014 -4,590 -2.61 126,046 14.00 0.5035
2023-02-10 2022-12-31 13F TRANSDIGM GROUP COM 893641100 175,604 1,469 0.84 110,569 20.99 0.4808
2022-11-09 2022-09-30 13F TRANSDIGM GROUP COM 893641100 174,135 -1,423 -0.81 91,390 -3.00 0.4197
2022-08-10 2022-06-30 13F TRANSDIGM GROUP COM 893641100 175,558 659 0.38 94,217 -17.32 0.4180
2022-05-13 2022-03-31 13F TRANSDIGM GROUP COM 893641100 174,899 -3,419 -1.92 113,954 0.44 0.3994
2022-02-14 2021-12-31 13F TRANSDIGM GROUP COM 893641100 178,318 -3,232 -1.78 113,460 0.06 0.3559
2021-11-12 2021-09-30 13F TRANSDIGM GROUP COM 893641100 181,550 -1,601 -0.87 113,391 -4.35 0.3860
2021-08-12 2021-06-30 13F TRANSDIGM GROUP COM 893641100 183,151 -1,814 -0.98 118,552 9.02 0.4108
2021-05-13 2021-03-31 13F TRANSDIGM GROUP COM 893641100 184,965 -929 -0.50 108,745 -5.47 0.4102
2021-02-09 2020-12-31 13F TRANSDIGM GROUP COM 893641100 185,894 -4,491 -2.36 115,040 27.18 0.4217
2020-11-06 2020-09-30 13F TRANSDIGM GROUP COM 893641100 190,385 -426 -0.22 90,456 7.24 0.3837
2020-08-12 2020-06-30 13F TRANSDIGM GROUP COM 893641100 190,811 32,357 20.42 84,348 66.25 0.4022
2020-05-11 2020-03-31 13F TRANSDIGM GROUP COM 893641100 158,454 -5,375 -3.28 50,735 -44.70 0.3171
2020-02-13 2019-12-31 13F TRANSDIGM GROUP COM 893641100 163,829 319 0.20 91,744 0.4715
2019-11-12 2019-09-30 13F TRANSDIGM GROUP COM 893641100 163,510 -4,679 -2.78 0 -100.00
2019-08-13 2019-06-30 13F TRANSDIGM GROUP COM 893641100 168,189 1,709 1.03 81,370 7.66 0.4653
2019-05-14 2019-03-31 13F TRANSDIGM GROUP COM 893641100 166,480 2,851 1.74 75,580 35.83 0.4608
2019-02-14 2018-12-31 13F TRANSDIGM GROUP COM 893641100 163,629 -4,077 -2.43 55,644 -10.88 0.4064
2018-11-13 2018-09-30 13F TRANSDIGM GROUP COM 893641100 167,706 1,256 0.75 62,437 8.68 0.3825
2018-08-13 2018-06-30 13F TRANSDIGM GROUP COM 893641100 166,450 659 0.40 57,449 12.89 0.3907
2018-05-15 2018-03-31 13F TRANSDIGM GROUP COM 893641100 165,791 -1,860 -1.11 50,888 10.53 0.3599
2018-02-14 2017-12-31 13F TRANSDIGM GROUP COM 893641100 167,651 -1,717 -1.01 46,040 6.33 0.3125
2017-11-13 2017-09-30 13F TRANSDIGM GROUP COM 893641100 169,368 -4,673 -2.68 43,299 -7.47 0.3247
2017-08-04 2017-06-30 13F TRANSDIGM GROUP COM 893641100 174,041 -15,119 -7.99 46,794 12.24 0.3514
2017-05-10 2017-03-31 13F TRANSDIGM GROUP COM 893641100 189,160 -69,277 -26.81 41,692 -35.20 0.3360
2017-02-14 2016-12-31 13F TRANSDIGM GROUP COM 893641100 258,437 -3,988 -1.52 64,340 -15.20 0.5755
2016-11-14 2016-09-30 13F TRANSDIGM GROUP COM 893641100 262,425 -2,868 -1.08 75,872 8.46 0.6706
2016-08-08 2016-06-30 13F TRANSDIGM GROUP COM 893641100 265,293 -794 -0.30 69,955 19.32 0.6523
2016-05-16 2016-03-31 13F TRANSDIGM GROUP COM 893641100 266,087 -1,086 -0.41 58,629 -3.94 0.5519
2016-02-16 2015-12-31 13F TRANSDIGM GROUP COM 893641100 267,173 -79,892 -23.02 61,035 -17.21 0.5731
2015-11-12 2015-09-30 13F TRANSDIGM GROUP COM 893641100 347,065 -901,667 -72.21 73,720 -73.72 0.6378
2015-08-03 2015-06-30 13F TRANSDIGM GROUP COM 893641100 1,248,732 60,651 5.10 280,552 7.96 0.4196
2015-05-11 2015-03-31 13F TRANSDIGM GROUP COM 893641100 1,188,081 1,188,081 0.00 259,856 0.4000
2015-02-05 2014-12-31 13F TRANSDIGM GROUP COM 893641100 0 -1,198,412 -100.00 0 -100.00
2014-11-04 2014-09-30 13F TRANSDIGM GROUP COM 893641100 1,198,412 -9,677 -0.80 220,903 9.32 0.3779
2014-08-01 2014-06-30 13F TRANSDIGM GROUP COM 893641100 1,208,089 -440,113 -26.70 202,065 -33.80 0.3300
2014-05-06 2014-03-31 13F TRANSDIGM GROUP COM 893641100 1,648,202 300,579 22.30 305,247 40.67 0.5050
2014-02-11 2013-12-31 13F TRANSDIGM GROUP COM 893641100 1,347,623 109,808 8.87 216,994 26.39 0.3587
2013-11-12 2013-09-30 13F TRANSDIGM GROUP COM 893641100 1,237,815 126,035 11.34 171,684 -1.50 0.3053
2013-08-07 2013-06-30 13F TRANSDIGM GROUP COM 893641100 1,111,780 1,111,780 174,293 0.3447
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2017-11-13 2017-09-30 13F TRANSDIGM GROUP OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-08-04 2017-06-30 13F TRANSDIGM GROUP OPTION Call 300 0.00 81 22.73 n/a n/a n/a
2017-05-10 2017-03-31 13F TRANSDIGM GROUP OPTION Call 300 0.00 66 -10.81 n/a n/a n/a
2017-02-14 2016-12-31 13F TRANSDIGM GROUP OPTION Call 300 74 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.