Tetra Tech, Inc.
US ˙ NasdaqGS ˙ US88162G1031

SecurityTTEK / Tetra Tech, Inc.
InstitutionParallel Advisors, LLC
Latest Disclosed Ownership4,440 shares
Latest Disclosed Value $ 148,940
Parallel Advisors, LLC ownership in TTEK / Tetra Tech, Inc.

On February 11, 2026 - Parallel Advisors, LLC filed a 13F-HR form disclosing ownership of 4,440 shares of Tetra Tech, Inc. (US:TTEK) valued at $148,918 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 4,982 shares of Tetra Tech, Inc.. This represents a change in shares of -10.88% during the quarter. The current value of the position is $123,432 USD.

Parallel Advisors, LLC has a history of taking positions in derivatives of the underlying security (TTEK) 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.

TTEK / Tetra Tech, Inc. 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)
2026-02-11 2025-12-31 13F TETRA TECH INC Stock 88162G103 4,440 -542 -10.88 149 -10.84 0.0027
2025-11-13 2025-09-30 13F TETRA TECH INC Stock 88162G103 4,982 574 13.02 166 5.06 0.0030
2025-07-08 2025-06-30 13F TETRA TECH INC Stock 88162G103 4,408 1,231 38.75 159 71.74 0.0032
2025-04-08 2025-03-31 13F TETRA TECH INC Stock 88162G103 3,177 2,075 188.29 93 113.95 0.0021
2025-02-10 2024-12-31 13F TETRA TECH INC Stock 88162G103 1,102 -4 -0.36 44 -17.31 0.0010
2024-11-13 2024-09-30 13F TETRA TECH INC Stock 88162G103 1,106 710 179.29 52 -35.80 0.0012
2024-08-08 2024-06-30 13F TETRA TECH INC Stock 88162G103 396 24 6.45 81 19.12 0.0021
2024-05-06 2024-03-31 13F TETRA TECH INC Stock 88162G103 372 -4 -1.06 69 9.68 0.0019
2024-02-12 2023-12-31 13F TETRA TECH INC Stock 88162G103 376 38 11.24 63 21.57 0.0019
2024-05-20 2023-09-30 13F/A-1 TETRA TECH INC Stock 88162G103 338 45 15.36 51 8.51 0.0017
2023-11-14 2023-09-30 13F TETRA TECH INC Stock 88162G103 338 45 51 0.0017
2024-05-20 2023-06-30 13F/A-1 TETRA TECH INC Stock 88162G103 293 84 40.19 48 56.67 0.0015
2023-08-04 2023-06-30 13F TETRA TECH INC Stock 88162G103 293 84 48 0.0015
2024-05-20 2023-03-31 13F/A-1 TETRA TECH INC Stock 88162G103 209 109 109.00 31 114.29 0.0010
2023-04-25 2023-03-31 13F TETRA TECH INC Stock 88162G103 209 109 31 0.0010
2023-02-06 2022-12-31 13F TETRA TECH INC Stock 88162G103 100 5 5.26 15 16.67 0.0006
2022-11-10 2022-09-30 13F TETRA TECH INC Stock 88162G103 95 -24 -20.17 12 -25.00 0.0006
2022-08-01 2022-06-30 13F TETRA TECH INC Stock 88162G103 119 -59 -33.15 16 -46.67 0.0007
2022-04-28 2022-03-31 13F TETRA TECH INC Stock 88162G103 178 -45 -20.18 30 -21.05 0.0012
2022-01-20 2021-12-31 13F TETRA TECH INC Stock 88162G103 223 34 17.99 38 35.71 0.0014
2021-11-02 2021-09-30 13F/A-1 TETRA TECH INC Stock 88162G103 189 51 36.96 28 64.71 0.0011
2021-08-06 2021-06-30 13F TETRA TECH INC Stock 88162G103 138 55 66.27 17 54.55 0.0007
2021-04-23 2021-03-31 13F TETRA TECH INC Stock 88162G103 83 15 22.06 11 37.50 0.0005
2021-02-02 2020-12-31 13F TETRA TECH INC Stock 88162G103 68 0 0.00 8 33.33 0.0004
2020-10-27 2020-09-30 13F TETRA TECH INC Stock 88162G103 68 0 0.00 6 20.00 0.0004
2020-07-16 2020-06-30 13F TETRA TECH INC Stock 88162G103 68 -185 -73.12 5 -70.59 0.0003
2020-04-27 2020-03-31 13F TETRA TECH INC Stock 88162G103 253 -84 -24.93 17 -41.38 0.0014
2020-01-30 2019-12-31 13F TETRA TECH INC Stock 88162G103 337 0 0.00 29 0.00 0.0022
2019-11-01 2019-09-30 13F TETRA TECH INC Stock 88162G103 337 129 62.02 29 81.25 0.0025
2019-08-05 2019-06-30 13F TETRA TECH INC Stock 88162G103 208 0 0.00 16 33.33 0.0016
2019-05-01 2019-03-31 13F TETRA TECH INC Stock 88162G103 208 196 1,633.33 12 0.0013
2019-02-05 2018-12-31 13F TETRA TECH INC Stock 88162G103 12 0 0.00 0 -100.00
2018-11-01 2018-09-30 13F TETRA TECH INC Stock 88162G103 12 0 0.00 1 0.0001
2018-07-30 2018-06-30 13F TETRA TECH INC Stock 88162G103 12 0 0.00 0 -100.00
2018-05-08 2018-03-31 13F TETRA TECH INC Stock 88162G103 12 0 0.00 1 0.00 0.0002
2018-02-13 2017-12-31 13F TETRA TECH INC NEW COM Stock 88162G103 12 0 0.00 1 0.00 0.0002
2017-11-15 2017-09-30 13F/A-1 TETRA TECH INC NEW COM Stock 88162G103 12 -7 -36.84 1 0.00 0.0002
2017-08-07 2017-06-30 13F TETRA TECH INC NEW COM Stock 88162G103 19 7 58.33 1 0.00 0.0002
2017-05-12 2017-03-31 13F/A-1 TETRA TECH INC NEW COM Stock 88162G103 12 0 0.00 1 0.00 0.0002
2017-05-12 2017-03-31 13F TETRA TECH INC NEW COM Stock 88162G103 12 1
2017-02-14 2016-12-31 13F TETRA TECH INC NEW COM Stock 88162G103 12 12 1 0.0002
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
(%)
2022-01-19 2021-12-31 13F TETRA TECH INC Stock Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-10-22 2021-09-30 13F TETRA TECH INC Stock Call 138 17 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.