Tetra Tech, Inc.
US ˙ NasdaqGS ˙ US88162G1031

SecurityTTEK / Tetra Tech, Inc.
InstitutionMorgan Stanley
Latest Disclosed Ownership2,239,504 shares
Latest Disclosed Value $ 67,453,924
Morgan Stanley reports 3.50% decrease in ownership of TTEK / Tetra Tech, Inc.

On May 15, 2026 - Morgan Stanley filed a 13F-HR form disclosing ownership of 2,239,504 shares of Tetra Tech, Inc. (US:TTEK) valued at $67,453,860 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on May 27, 2026 disclosing 2,320,740 shares of Tetra Tech, Inc.. This represents a change in shares of -3.50% during the quarter. The current value of the position is $62,638,927 USD.

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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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)
2026-05-15 2026-03-31 13F TETRA TECH INC COM 88162G103 2,239,504 -81,236 -3.50 67,454 -13.34 0.0041
2026-05-27 2025-12-31 13F/A-1 TETRA TECH INC COM 88162G103 2,320,740 -60,656 -2.55 77,838 -2.08 0.0046
2026-02-13 2025-12-31 13F TETRA TECH INC COM 88162G103 2,320,740 -60,656 77,838 0.0046
2026-05-27 2025-09-30 13F/A-1 TETRA TECH INC COM 88162G103 2,381,396 -313,270 -11.63 79,491 -17.97 0.0048
2025-11-14 2025-09-30 13F TETRA TECH INC COM 88162G103 2,381,396 -313,270 79,491 0.0048
2025-08-15 2025-06-30 13F TETRA TECH INC COM 88162G103 2,694,666 -336,326 -11.10 96,900 9.30 0.0063
2025-05-15 2025-03-31 13F TETRA TECH INC COM 88162G103 3,030,992 695,761 29.79 88,657 -4.71 0.0063
2025-05-15 2024-12-31 13F/A-1 TETRA TECH INC COM 88162G103 2,335,231 9,644 0.41 93,036 -15.17 0.0065
2025-02-14 2024-12-31 13F TETRA TECH INC COM 88162G103 2,335,231 9,644 93,036 0.0065
2025-05-14 2024-09-30 13F/A-2 TETRA TECH INC COM 88162G103 2,325,587 1,788,689 333.15 109,675 -0.10 0.0080
2025-02-14 2024-09-30 13F/A-1 TETRA TECH INC COM 88162G103 2,325,587 1,788,689 109,675 0.0080
2024-11-14 2024-09-30 13F TETRA TECH INC COM 88162G103 2,325,587 1,788,689 109,675 0.0080
2025-05-14 2024-06-30 13F/A-2 TETRA TECH INC COM 88162G103 536,898 -839 -0.16 109,785 10.53 0.0085
2024-10-17 2024-06-30 13F/A-1 TETRA TECH INC COM 88162G103 536,898 -839 109,785 0.0085
2024-08-14 2024-06-30 13F TETRA TECH INC COM 88162G103 536,898 -839 109,785 0.0085
2024-10-17 2024-03-31 13F/A-2 TETRA TECH INC COM 88162G103 537,737 -141,455 -20.83 99,326 -12.39 0.0080
2024-08-16 2024-03-31 13F/A-1 TETRA TECH INC COM 88162G103 537,737 -141,455 99,326 0.0009
2024-05-15 2024-03-31 13F TETRA TECH INC COM 88162G103 537,737 -141,455 99,326 0.0080
2024-08-16 2023-12-31 13F/A-1 TETRA TECH INC COM 88162G103 679,192 62,424 10.12 113,378 20.91 0.0100
2024-02-13 2023-12-31 13F TETRA TECH INC COM 88162G103 679,192 62,424 113,378 0.0100
2023-11-15 2023-09-30 13F TETRA TECH INC COM 88162G103 616,768 34,259 5.88 93,768 -1.69 0.0095
2023-08-14 2023-06-30 13F TETRA TECH INC COM 88162G103 582,509 -8,653 -1.46 95,380 9.83 0.0094
2023-05-15 2023-03-31 13F TETRA TECH INC COM 88162G103 591,162 -11,603 -1.92 86,848 -0.76 0.0093
2023-02-14 2022-12-31 13F TETRA TECH INC COM 88162G103 602,765 243,312 67.69 87,516 89.43 0.0099
2022-11-14 2022-09-30 13F TETRA TECH INC COM 88162G103 359,453 -22,030 -5.77 46,199 -11.31 0.0063
2022-10-27 2022-06-30 13F/A-1 TETRA TECH INC COM 88162G103 381,483 191,923 101.25 52,092 66.61 0.0068
2022-08-15 2022-06-30 13F TETRA TECH INC COM 88162G103 381,483 191,923 52,092 0.0014
2022-10-27 2022-03-31 13F/A-1 TETRA TECH INC COM 88162G103 189,560 -43,660 -18.72 31,265 -21.05 0.0042
2022-05-13 2022-03-31 13F TETRA TECH INC COM 88162G103 189,560 -43,660 31,265 0.0042
2022-02-14 2021-12-31 13F TETRA TECH INC COM 88162G103 233,220 17,598 8.16 39,601 22.98 0.0049
2021-11-15 2021-09-30 13F TETRA TECH INC COM 88162G103 215,622 -37,392 -14.78 32,201 4.28 0.0043
2021-08-23 2021-06-30 13F/A-1 TETRA TECH INC COM 88162G103 253,014 38,853 18.14 30,878 6.24 0.0041
2021-08-16 2021-06-30 13F TETRA TECH INC COM 88162G103 253,014 38,853 30,878 0.0008
2021-05-17 2021-03-31 13F TETRA TECH INC COM 88162G103 214,161 -124,274 -36.72 29,065 -25.83 0.0043
2021-02-16 2020-12-31 13F TETRA TECH INC COM 88162G103 338,435 219,005 183.38 39,185 243.55 0.0061
2020-11-13 2020-09-30 13F TETRA TECH INC COM 88162G103 119,430 -24,361 -16.94 11,406 0.25 0.0022
2020-08-14 2020-06-30 13F TETRA TECH INC COM 88162G103 143,791 -31,304 -17.88 11,377 -7.99 0.0025
2020-05-26 2020-03-31 13F/A-1 TETRA TECH INC COM 88162G103 175,095 -114,837 -39.61 12,365 -50.50 0.0034
2020-05-15 2020-03-31 13F TETRA TECH INC COM 88162G103 175,095 -114,837 12,365 949.8898
2020-02-14 2019-12-31 13F TETRA TECH INC COM 88162G103 289,932 111,577 62.56 24,980 61.43 0.0058
2019-11-14 2019-09-30 13F TETRA TECH INC COM 88162G103 178,355 -189,649 -51.53 15,474 -46.47 0.0041
2019-08-14 2019-06-30 13F TETRA TECH INC COM 88162G103 368,004 111,248 43.33 28,908 88.94 0.0077
2019-05-15 2019-03-31 13F TETRA TECH INC COM 88162G103 256,756 -386,405 -60.08 15,300 -54.05 0.0043
2019-02-14 2018-12-31 13F TETRA TECH INC COM 88162G103 643,161 122,765 23.59 33,296 -6.32 0.0100
2019-04-23 2018-09-30 13F/A-2 TETRA TECH INC COM 88162G103 520,396 177,506 51.77 35,544 77.19 0.0089
2018-11-20 2018-09-30 13F/A-1 TETRA TECH INC COM 88162G103 520,396 0 35,544 0.0089
2018-11-14 2018-09-30 13F TETRA TECH INC COM 88162G103 520,396 177,506 35,544
2019-04-23 2018-06-30 13F/A-1 TETRA TECH INC COM 88162G103 342,890 -19,208 -5.30 20,060 13.18 0.0054
2018-08-14 2018-06-30 13F TETRA TECH INC COM 88162G103 342,890 -19,208 20,060
2019-04-23 2018-03-31 13F/A-1 TETRA TECH INC COM 88162G103 362,098 26,898 8.02 17,724 9.81 0.0049
2018-05-14 2018-03-31 13F TETRA TECH INC COM 88162G103 362,098 26,898 17,724
2019-04-23 2017-12-31 13F/A-1 TETRA TECH INC COM 88162G103 335,200 109,667 48.63 16,140 53.74 0.0044
2018-02-14 2017-12-31 13F TETRA TECH INC COM 88162G103 335,200 109,667 16,140
2017-11-14 2017-09-30 13F TETRA TECH INC COM 88162G103 225,533 -40,686 -15.28 10,498 -13.80 0.0031
2017-08-11 2017-06-30 13F TETRA TECH INC COM 88162G103 266,219 -86,568 -24.54 12,179 -15.49 0.0037
2017-05-22 2017-03-31 13F/A-1 TETRA TECH INC COM 88162G103 352,787 -23,344 -6.21 14,411 -11.21 0.0044
2017-05-12 2017-03-31 13F TETRA TECH INC COM 88162G103 352,787 14,411
2017-02-22 2016-12-31 13F/A-1 TETRA TECH INC COM 88162G103 376,131 87,089 30.13 16,230 58.31 0.0053
2017-02-13 2016-12-31 13F TETRA TECH INC COM 88162G103 376,131 16,230
2016-11-10 2016-09-30 13F TETRA TECH INC COM 88162G103 289,042 65,925 29.55 10,252 49.47 0.0035
2016-08-12 2016-06-30 13F TETRA TECH INC COM 88162G103 223,117 -306,560 -57.88 6,859 -56.57 0.0025
2016-05-12 2016-03-31 13F TETRA TECH INC COM 88162G103 529,677 157,949 42.49 15,795 63.31 0.0061
2016-02-09 2015-12-31 13F TETRA TECH INC COM 88162G103 371,728 -173,730 -31.85 9,672 -27.06 0.0035
2016-02-08 2015-09-30 13F/A-1 TETRA TECH INC COM 88162G103 545,458 288,266 112.08 13,260 101.06 0.0049
2015-11-09 2015-09-30 13F TETRA TECH INC COM 88162G103 545,458 13,260
2015-08-12 2015-06-30 13F TETRA TECH INC COM 88162G103 257,192 -151,349 -37.05 6,595 -32.79 0.0023
2015-05-14 2015-03-31 13F TETRA TECH INC COM 88162G103 408,541 205,807 101.52 9,813 81.29 0.0036
2015-02-13 2014-12-31 13F TETRA TECH INC COM 88162G103 202,734 44,801 28.37 5,413 37.25 0.0020
2014-12-16 2014-09-30 13F/A-1 TETRA TECH INC COM 88162G103 157,933 -41,566 -20.84 3,944 -33.19 0.0015
2014-11-14 2014-09-30 13F TETRA TECH INC COM 88162G103 157,933 3,944
2014-05-13 2014-03-31 13F TETRA TECH INC COM 88162G103 199,499 -8,348 -4.02 5,903 1.51 0.0025
2014-02-13 2013-12-31 13F TETRA TECH INC COM 88162G103 207,847 154,444 289.20 5,815 320.77 0.0025
2013-11-13 2013-09-30 13F TETRA TECH INC COM ST COM 88162G103 53,403 -10,270 -16.13 1,382 -7.68 0.0007
2013-08-08 2013-06-30 13F TETRA TECH INC COM ST COM 88162G103 63,673 63,673 1,497 0.0008
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.