Tetra Tech, Inc.
US ˙ NasdaqGS ˙ US88162G1031

SecurityTTEK / Tetra Tech, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership272,525 shares
Latest Disclosed Value $ 9,140,159
Sei Investments Co reports 41.89% decrease in ownership of TTEK / Tetra Tech, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 272,525 shares of Tetra Tech, Inc. (US:TTEK) valued at $9,140,488 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 468,993 shares of Tetra Tech, Inc.. This represents a change in shares of -41.89% during the quarter. The current value of the position is $7,622,524 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)
2026-02-13 2025-12-31 13F TETRA TECH INC COM 88162G103 272,525 -196,468 -41.89 9,140 -41.61 0.0090
2025-11-13 2025-09-30 13F TETRA TECH INC COM 88162G103 468,993 -21,805 -4.44 15,655 -11.30 0.0168
2025-08-14 2025-06-30 13F TETRA TECH INC COM 88162G103 490,798 96,475 24.47 17,650 53.02 0.0205
2025-05-14 2025-03-31 13F/A-1 TETRA TECH INC COM 88162G103 394,323 -123,763 -23.89 11,534 -44.12 0.0148
2025-05-13 2025-03-31 13F TETRA TECH INC COM 88162G103 528,629 10,543 20,278 0.0221
2025-02-11 2024-12-31 13F TETRA TECH INC COM 88162G103 518,086 -124,132 -19.33 20,642 -31.85 0.0265
2024-11-12 2024-09-30 13F TETRA TECH INC COM 88162G103 642,218 552,469 615.57 30,286 65.04 0.0393
2024-08-13 2024-06-30 13F TETRA TECH INC COM 88162G103 89,749 -7,996 -8.18 18,352 1.65 0.0260
2024-05-07 2024-03-31 13F TETRA TECH INC COM 88162G103 97,745 3,049 3.22 18,054 14.22 0.0265
2024-02-14 2023-12-31 13F TETRA TECH INC COM 88162G103 94,696 -24,489 -20.55 15,807 -12.76 0.0254
2023-11-14 2023-09-30 13F TETRA TECH INC COM 88162G103 119,185 -2,108 -1.74 18,119 -8.77 0.0326
2023-08-11 2023-06-30 13F TETRA TECH INC COM 88162G103 121,293 -16,281 -11.83 19,860 -1.74 0.0346
2023-05-12 2023-03-31 13F TETRA TECH INC COM 88162G103 137,574 104,346 314.03 20,211 318.97 0.0375
2023-02-10 2022-12-31 13F TETRA TECH INC COM 88162G103 33,228 -88,204 -72.64 4,825 -69.09 0.0107
2022-11-14 2022-09-30 13F TETRA TECH INC COM 88162G103 121,432 8,875 7.88 15,608 1.32 0.0348
2022-08-15 2022-06-30 13F TETRA TECH INC COM 88162G103 112,557 95,927 576.83 15,405 462.64 0.0333
2022-05-13 2022-03-31 13F TETRA TECH INC COM 88162G103 16,630 -980 -5.57 2,738 -9.82 0.0055
2022-02-14 2021-12-31 13F TETRA TECH INC COM 88162G103 17,610 13,005 282.41 3,036 350.45 0.0057
2021-11-12 2021-09-30 13F TETRA TECH INC COM 88162G103 4,605 2,195 91.08 674 127.70 0.0014
2021-08-06 2021-06-30 13F TETRA TECH INC COM 88162G103 2,410 -7,540 -75.78 296 -74.28 0.0007
2021-05-12 2021-03-31 13F TETRA TECH INC COM 88162G103 9,950 0 0.00 1,151 0.00 0.0029
2021-02-08 2020-12-31 13F TETRA TECH INC COM 88162G103 9,950 6,284 171.41 1,151 219.72 0.0030
2020-12-04 2020-09-30 13F/A-1 TETRA TECH INC COM 88162G103 3,666 282 8.33 360 36.36 0.0010
2020-11-06 2020-09-30 13F TETRA TECH INC COM 88162G103 4,354 970 426 1,025.7133
2020-08-17 2020-06-30 13F/A-1 TETRA TECH INC COM 88162G103 3,384 -7,437 -68.73 264 -65.49 0.0008
2020-05-14 2020-03-31 13F TETRA TECH INC COM 88162G103 10,821 3,765 53.36 765 25.82 0.0028
2020-02-06 2019-12-31 13F TETRA TECH INC COM 88162G103 7,056 -1,868 -20.93 608 -21.45 0.0018
2019-11-12 2019-09-30 13F TETRA TECH INC COM 88162G103 8,924 444 5.24 774 16.22 0.0020
2019-08-14 2019-06-30 13F TETRA TECH INC COM 88162G103 8,480 -62,537 -88.06 666 -84.26 0.0022
2019-05-15 2019-03-31 13F TETRA TECH INC COM 88162G103 71,017 46,476 189.38 4,231 236.06 0.0142
2019-02-13 2018-12-31 13F TETRA TECH INC COM 88162G103 24,541 23,054 1,550.37 1,259 1,298.89 0.0045
2018-11-08 2018-09-30 13F TETRA TECH INC COM 88162G103 1,487 -13,549 -90.11 90 -89.77 0.0003
2018-08-03 2018-06-30 13F TETRA TECH INC COM 88162G103 15,036 -4,929 -24.69 880 -9.93 0.0030
2018-05-11 2018-03-31 13F TETRA TECH INC COM 88162G103 19,965 6,727 50.82 977 53.38 0.0037
2018-02-08 2017-12-31 13F TETRA TECH INC COM 88162G103 13,238 -4,667 -26.07 637 -23.62 0.0022
2017-11-06 2017-09-30 13F TETRA TECH INC COM 88162G103 17,905 -42,873 -70.54 834 -70.00 0.0030
2017-07-31 2017-06-30 13F TETRA TECH INC COM 88162G103 60,778 46,665 330.65 2,780 382.64 0.0111
2017-05-05 2017-03-31 13F TETRA TECH INC COM 88162G103 14,113 -41,995 -74.85 576 -76.21 0.0025
2017-02-02 2016-12-31 13F TETRA TECH INC COM 88162G103 56,108 36,652 188.38 2,421 250.87 0.0117
2016-11-04 2016-09-30 13F TETRA TECH INC COM 88162G103 19,456 6,798 53.71 690 77.38 0.0035
2016-08-11 2016-06-30 13F TETRA TECH INC COM 88162G103 12,658 7,565 148.54 389 155.92 0.0023
2016-05-10 2016-03-31 13F/A-1 TETRA TECH INC COM 88162G103 5,093 1,249 32.49 152 52.00 0.0009
2016-02-03 2015-12-31 13F TETRA TECH INC COM 88162G103 3,844 2,348 156.95 100 177.78 0.0006
2015-11-02 2015-09-30 13F/A-1 TETRA TECH INC COM 88162G103 1,496 722 93.28 36 80.00 0.0003
2015-10-30 2015-09-30 13F DIREXION SHS ETF TR COM 88162G103 1,496 37
2015-08-07 2015-06-30 13F/A-1 TETRA TECH INC COM 88162G103 774 -149 -16.14 20 -13.04 0.0002
2015-08-04 2015-06-30 13F TETRA TECH INC COM 88162G103 774 -149 20 0.0002
2015-05-14 2015-03-31 13F/A-1 TETRA TECH INC COM 88162G103 923 -108 -10.48 23 -23.33 0.0002
2015-05-01 2015-03-31 13F TETRA TECH INC COM 88162G103 923 23
2015-02-10 2014-12-31 13F TETRA TECH INC COM 88162G103 1,031 1,031 30 0.0003
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.