# EDGAR Filing Document

**Accession Number:** 0001361570
**File Stem:** 0001361570-25-000021
**Filing Date:** 2025-10
**Character Count:** 14358
**Document Hash:** 0a77abfd270c71f50e58c254d00b9e0d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001361570-25-000021.hdr.sgml**: 20251017

**ACCESSION NUMBER**: 0001361570-25-000021

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251017

**DATE AS OF CHANGE**: 20251017

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** TETRA TECH INC
- **CENTRAL INDEX KEY:** 0000831641
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-ENGINEERING SERVICES [8711]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 954148514
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0928

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-43035
- **FILM NUMBER:** 251399844

**BUSINESS ADDRESS:**
- **STREET 1:** 3475 EAST FOOTHILL BOULEVARD
- **CITY:** PASADENA
- **STATE:** CA
- **ZIP:** 91107
- **BUSINESS PHONE:** 6263514664

**MAIL ADDRESS:**
- **STREET 1:** 3475 EAST FOOTHILL BOULEVARD
- **CITY:** PASADENA
- **STATE:** CA
- **ZIP:** 91107
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** PICTET ASSET MANAGEMENT SA
- **CENTRAL INDEX KEY:** 0001361570

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** V8
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 60 ROUTE DE ACACIAS
- **CITY:** GENEVA 73
- **STATE:** V8
- **ZIP:** 1211
- **BUSINESS PHONE:** 011 44 207 847 5040

**MAIL ADDRESS:**
- **STREET 1:** 60 ROUTE DE ACACIAS
- **CITY:** GENEVA 73
- **STATE:** V8
- **ZIP:** 1211

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 2)**

**TETRA TECH INC**

*(Name of Issuer)*

**COMMON STOCK**

*(Title of Class of Securities)*

**88162G103**

*(CUSIP Number)*

**Mathieu Cornu**<br>Route des Acacias 60<br>Geneva V8 1211<br>0041583234506

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**10/16/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **88162G103** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**PICTET ASSET MANAGEMENT SA** | Name of reporting person<br>**PICTET ASSET MANAGEMENT SA** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**V8** | Citizenship or place of organization<br>**V8** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**11829824.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**13006243.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**13006243.00** | Aggregate amount beneficially owned by each reporting person<br>**13006243.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**4.9%** | Percent of class represented by amount in Row (11)<br>**4.9%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IA** | Type of Reporting Person (See Instructions)<br>**IA** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
COMMON STOCK

**(b) Name of Issuer:**
TETRA TECH INC

**(c) Address of Issuer's Principal Executive Offices:**
3475 EAST FOOTHILL BOULEVARD, PASADENA, CA, 91107

**Item 4. Purpose of Transaction**

The Reporting Person acquired shares of Tetra Tech Inc. as part of its investment strategy, considering the clarity and robustness of the issuer's long-term strategy; the functioning and calibre of governance structures and effective leadership; the financial strength and performance of issuers and the fair valuation of underlying securities; and financially-material sustainability risks & opportunities. The Reporting Person is therefore actively engaging with the Issuer to discuss and promote initiatives that align with these business practices.

This engagement is part of the Reporting Person's broader strategy to support companies in enhancing their approach, thereby potentially improving long-term shareholder value. As such, the Reporting Person may seek to influence the Issuer's policies and practices through discussions with the Boards and management of the companies in which we invest.

The Reporting Person does not currently have any plans or proposals that would result in a change in control of the Issuer, nor does it intend to acquire additional shares for the purpose of gaining control. However, the Reporting Person reserves the right to change its intentions and take any actions that it deems appropriate in light of its ongoing engagement and evaluation of the Issuer's policies and practices.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Pictet Asset management SA manages 13,006,243 shares of Tetra Tech Inc., which represents 4.9% of the total number of shares.

**(b)**
Pictet Asset management SA has the Sole power to vote on 11,829,824 out of the 13,006,243 shares under management.

**(c)**
In the past sixty days the following transactions have been done

Date          	Type  	Quantity 	Price	        Exchange
08.20.2025	SELLL	24827	35.76	The NASDAQ Stock Exchange
08.20.2025	SELLL	248  	35.76	The NASDAQ Stock Exchange
08.20.2025	SELLL	543  	35.76	The NASDAQ Stock Exchange
08.20.2025	SELLL	717  	35.76	The NASDAQ Stock Exchange
08.26.2025	BUYL	1467	36.64	The NASDAQ Stock Exchange
08.27.2025	SELLL	50    	36.98	The NASDAQ Stock Exchange
08.27.2025	SELLL	8912	36.84	The NASDAQ Stock Exchange
08.29.2025	BUYL	148  	36.42	The NASDAQ Stock Exchange
09.03.2025	SELLL	33809	35.96	The NASDAQ Stock Exchange
09.03.2025	SELLL	2371	35.91	The NASDAQ Stock Exchange
09.03.2025	SELLL	91211	35.91	The NASDAQ Stock Exchange
09.03.2025	SELLL	1150	35.91	The NASDAQ Stock Exchange
09.03.2025	SELLL	909  	35.91	The NASDAQ Stock Exchange
09.03.2025	SELLL	1330	35.96	The NASDAQ Stock Exchange
09.03.2025	BUYL	3143	35.96	The NASDAQ Stock Exchange
09.03.2025	BUYL	6847	35.83	The NASDAQ Stock Exchange
09.03.2025	BUYL	2357	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	975  	35.83	The NASDAQ Stock Exchange
09.03.2025	BUYL	1988	35.83	The NASDAQ Stock Exchange
09.03.2025	BUYL	953  	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	988  	35.83	The NASDAQ Stock Exchange
09.03.2025	BUYL	2010	35.83	The NASDAQ Stock Exchange
09.03.2025	BUYL	966  	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	6672	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	1936	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	1963	35.78	The NASDAQ Stock Exchange
09.03.2025	BUYL	2415	35.83	The NASDAQ Stock Exchange
09.05.2025	SELLL	26591	36.09	The NASDAQ Stock Exchange
09.17.2025	SELLL	8230	36.48	The NASDAQ Stock Exchange
09.18.2025	BUYL	3722	36.38	The NASDAQ Stock Exchange
09.18.2025	BUYL	81    	36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	9405	36.38	The NASDAQ Stock Exchange
09.18.2025	BUYL	2648	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	26    	36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	3070	36.38	The NASDAQ Stock Exchange
09.18.2025	BUYL	945  	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	470  	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	16    	36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	1474	36.38	The NASDAQ Stock Exchange
09.18.2025	BUYL	39	        36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	1092	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	810  	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	26    	36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	3136	36.38	The NASDAQ Stock Exchange
09.18.2025	BUYL	464  	36.29	The NASDAQ Stock Exchange
09.18.2025	BUYL	12    	36.28	The NASDAQ Stock Exchange
09.18.2025	BUYL	1426	36.38	The NASDAQ Stock Exchange
09.18.2025	SELLL	288  	36.20	The NASDAQ Stock Exchange
09.18.2025	SELLL	9497	36.34	The NASDAQ Stock Exchange
09.18.2025	BUYL	3142	36.62	The NASDAQ Stock Exchange
09.19.2025	BUYL	1961	36.66	The NASDAQ Stock Exchange
09.19.2025	BUYL	2533	36.66	The NASDAQ Stock Exchange
09.23.2025	SELLL	585  	35.33	The NASDAQ Stock Exchange
09.24.2025	SELLL	2772	33.64	The NASDAQ Stock Exchange
09.25.2025	BUYL	550  	33.31	The NASDAQ Stock Exchange
09.25.2025	BUYL	1356	33.37	The NASDAQ Stock Exchange
09.26.2025	SELLL	175  	33.15	The NASDAQ Stock Exchange
09.30.2025	BUYL	33068	33.42	The NASDAQ Stock Exchange
10.02.2025	BUYL	1498	33.68	The NASDAQ Stock Exchange
10.01.2025	BUYL	1008	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	815  	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	1188	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	805  	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	3214	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	967  	33.29	The NASDAQ Stock Exchange
10.01.2025	BUYL	3279	33.19	The NASDAQ Stock Exchange
10.02.2025	SELLL	546          33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	932  	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	1012	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	333  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	410  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	552  	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	948  	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	1030	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	334  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	413  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	26651	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	68463	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	77128	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	3656	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	11893	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	326  	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	430  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	313  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	1191	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	2601	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	2893	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	417  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	694  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	2987	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	3364	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	537  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	1178	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	571  	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	996	        33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	1084	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	336  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	421  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	2307	33.42	The NASDAQ Stock Exchange
10.02.2025	SELLL	2589	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	394  	33.29	The NASDAQ Stock Exchange
10.02.2025	SELLL	477  	33.35	The NASDAQ Stock Exchange
10.02.2025	SELLL	956  	33.10	The NASDAQ Stock Exchange
10.02.2025	SELLL	81925	33.50	The NASDAQ Stock Exchange
10.03.2025	BUYL	15255	33.82	The NASDAQ Stock Exchange
10.03.2025	BUYL	5769	33.82	The NASDAQ Stock Exchange
10.07.2025	BUYL	5547	34.15	The NASDAQ Stock Exchange
10.08.2025	BUYL	5375	34.12	The NASDAQ Stock Exchange
10.08.2025	BUYL	2476	34.12	The NASDAQ Stock Exchange
10.09.2025	SELLL	778  	34.68	The NASDAQ Stock Exchange
10.09.2025	BUYL	6201	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	2352	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	2364	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	1904	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	6202	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	989  	34.47	The NASDAQ Stock Exchange
10.09.2025	BUYL	5422	34.47	The NASDAQ Stock Exchange
10.10.2025	SELLL	1806	34.33	The NASDAQ Stock Exchange
10.16.2025	SELLL	162899	32.71	The NASDAQ Stock Exchange
10.16.2025	SELLL	190050	32.68	The NASDAQ Stock Exchange
10.16.2025	SELLL	676  	32.49	The NASDAQ Stock Exchange
10.16.2025	SELLL	5619	32.71	The NASDAQ Stock Exchange
10.16.2025	SELLL	6189	32.68	The NASDAQ Stock Exchange
10.16.2025	SELLL	19416	32.49	The NASDAQ Stock Exchange
10.16.2025	SELLL	861  	32.68	The NASDAQ Stock Exchange
10.16.2025	SELLL	2338	32.71	The NASDAQ Stock Exchange
10.16.2025	SELLL	310  	32.49	The NASDAQ Stock Exchange
10.16.2025	SELLL	2900	32.68	The NASDAQ Stock Exchange
10.16.2025	SELLL	2787	32.71	The NASDAQ Stock Exchange
10.16.2025	SELLL	338  	32.49	The NASDAQ Stock Exchange
10.16.2025	BUYL	1218	32.68	The NASDAQ Stock Exchange

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

The Reporting Person's exposure to Tetra Tech Inc. is solely through direct stock investments held by its managed institutional clients. There are no contracts, arrangements, understandings, or relationships with any third parties regarding the securities of Tetra Tech Inc., other than those arising from the ordinary course of discretionary management of our client assets.

The Reporting Person does not have any derivative positions, options, or other financial instruments related to the securities of the Issuer. Furthermore, there are no agreements or understandings that would influence the voting or disposition of these securities beyond the Reporting Person's discretionary investment authority as an asset manager.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** PICTET ASSET MANAGEMENT SA

**Signature:** Karine Valtanen

**Name/Title:** Global Head of Compliance

**Date:** 10/17/2025