Tetra Tech, Inc.
US ˙ NasdaqGS ˙ US88162G1031

SecurityTTEK / Tetra Tech, Inc.
InstitutionWhittier Trust Co
Latest Disclosed Ownership1,915 shares
Latest Disclosed Value $ 59,729
Whittier Trust Co reports 94.18% decrease in ownership of TTEK / Tetra Tech, Inc.

On April 28, 2026 - Whittier Trust Co filed a 13F-HR form disclosing ownership of 1,915 shares of Tetra Tech, Inc. (US:TTEK) valued at $57,680 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 32,915 shares of Tetra Tech, Inc.. This represents a change in shares of -94.18% during the quarter. The current value of the position is $53,563 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)
2026-04-28 2026-03-31 13F TETRA TECH common 88162G103 1,915 -31,000 -94.18 60 -94.84 0.0007
2026-01-26 2025-12-31 13F TETRA TECH common 88162G103 32,915 0 0.00 1,144 3.06 0.0124
2025-10-31 2025-09-30 13F TETRA TECH INC common 88162G103 32,915 0 0.00 1,111 -6.17 0.0126
2025-07-30 2025-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 32,915 0 0.00 1,183 22.97 0.0143
2025-05-02 2025-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 32,915 -1,250 -3.66 963 -29.32 0.0134
2025-02-11 2024-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 34,165 -750 -2.15 1,361 -17.31 0.0179
2024-10-21 2024-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 34,915 28,082 410.98 1,646 17.82 0.0220
2024-07-29 2024-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,397 10.70 0.0198
2024-05-02 2024-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,262 10.70 0.0184
2024-01-11 2023-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,141 9.83 0.0185
2023-10-27 2023-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,039 -7.16 0.0185
2023-07-24 2023-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,119 11.47 0.0194
2023-04-21 2023-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 1,004 1.11 0.0183
2023-01-25 2022-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 0 0.00 992 12.98 0.0193
2022-10-21 2022-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,833 250 3.80 878 -2.34 0.0184
2022-07-28 2022-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,583 0 0.00 899 -17.22 0.0182
2022-04-29 2022-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,583 0 0.00 1,086 -2.86 0.0183
2022-01-19 2021-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,583 0 0.00 1,118 13.73 0.0182
2021-11-01 2021-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,583 0 0.00 983 22.26 0.0179
2021-07-29 2021-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,583 232 3.65 804 -6.62 0.0143
2021-04-26 2021-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 861 17.14 0.0167
2021-01-29 2020-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 735 21.29 0.0157
2020-10-30 2020-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 606 20.48 0.0144
2020-07-10 2020-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 503 12.03 0.0140
2020-04-27 2020-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 449 -17.92 0.0147
2020-01-31 2019-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 0 0.00 547 -0.73 0.0144
2019-10-18 2019-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,351 81 1.29 551 11.99 0.0158
2019-07-23 2019-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 492 31.90 0.0144
2019-04-29 2019-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 373 14.77 0.0114
2019-02-07 2018-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 325 -24.07 0.0112
2018-10-23 2018-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 428 16.62 0.0134
2018-07-27 2018-06-30 13F/A-1 TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 367 19.93 0.0121
2018-07-20 2018-06-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,200 -70 171
2018-05-01 2018-03-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 306 1.32 0.0103
2018-02-07 2017-12-31 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 302 3.42 0.0105
2017-10-23 2017-09-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 292 1.74 0.0106
2017-07-20 2017-06-30 13F TETRA TECH US SMALL-CAP EQUITIES 88162G103 6,270 0 0.00 287 12.11 0.0111
2017-04-26 2017-03-31 13F TETRA TECH INC US SMALL AND MID-CAP EQUITIES 88162G103 6,270 0 0.00 256 -5.54 0.0103
2017-01-18 2016-12-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,270 0 0.00 271 22.07 0.0115
2016-11-10 2016-09-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,270 0 0.00 222 15.03 0.0097
2016-07-28 2016-06-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,270 -900 -12.55 193 -9.81 0.0085
2016-04-28 2016-03-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 7,170 0 0.00 214 15.05 0.0095
2016-02-10 2015-12-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 7,170 0 0.00 186 6.29 0.0084
2015-11-12 2015-09-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 7,170 70 0.99 175 -3.85 0.0085
2015-08-13 2015-06-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 7,100 0 0.00 182 6.43 0.0081
2015-05-05 2015-03-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 7,100 7,100 0.00 171 0.0078
2015-02-04 2014-12-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 0 -6,200 -100.00 0 -100.00
2014-11-07 2014-09-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,200 0 0.00 155 -9.36 0.0076
2014-08-04 2014-06-30 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,200 0 0.00 171 -6.56 0.0084
2014-05-01 2014-03-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,200 0 0.00 183 5.78 0.0094
2014-02-05 2013-12-31 13F TETRA TECH US SMALL AND MID-CAP EQUITIES 88162G103 6,200 0 0.00 173 8.13 0.0089
2013-11-18 2013-09-30 13F TETRA TECH COM 88162G103 6,200 0 0.00 160 9.59 0.0087
2013-08-14 2013-06-30 13F TETRA TECH COM 88162G103 6,200 6,200 146 0.0082
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.