# EDGAR Filing Document

**Accession Number:** 0001571235
**File Stem:** 0001193125-26-111577
**Filing Date:** 2026-3
**Character Count:** 8598
**Document Hash:** 6132608b2eed7c959062da1002ccd435
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-111577.hdr.sgml**: 20260317

**ACCESSION NUMBER**: 0001193125-26-111577

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260315

**FILED AS OF DATE**: 20260317

**DATE AS OF CHANGE**: 20260317

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Gleason Todd R
- **CENTRAL INDEX KEY:** 0001571235

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-07099
- **FILM NUMBER:** 26764487

**MAIL ADDRESS:**
- **STREET 1:** 5500 WAYZATA BLVD., SUITE 800
- **CITY:** GOLDEN VALLEY
- **STATE:** MN
- **ZIP:** 55416
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** CECO ENVIRONMENTAL CORP
- **CENTRAL INDEX KEY:** 0000003197
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 132566064
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 5080 SPECTRUM DRIVE
- **STREET 2:** SUITE 800E
- **CITY:** ADDISON
- **STATE:** TX
- **ZIP:** 75001
- **BUSINESS PHONE:** (513) 458-2600

**MAIL ADDRESS:**
- **STREET 1:** 5080 SPECTRUM DRIVE
- **STREET 2:** SUITE 800E
- **CITY:** ADDISON
- **STATE:** TX
- **ZIP:** 75001

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** API ENTERPRISES INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ALARM PRODUCTS INTERNATIONAL INC
- **DATE OF NAME CHANGE:** 19851210

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Gleason Todd R<br><sub>(Last) (First) (Middle)</sub><br>5080 SPECTRUM DRIVE<br>SUITE 800E<br><sub>(Street)</sub><br>ADDISON, TX 75001<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-03-15 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Chief Executive Officer_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>CECO ENVIRONMENTAL CORP [ CECO ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-03-15 |  | A<sup>(1)</sup> |  | 75055 | A | $0 | 482333 | D |  |
| Common Stock | 2026-03-15 |  | F<sup>(2)</sup> |  | 29535 | D | $54.85 | 452798 | D |  |
| Common Stock |  |  |  |  |  |  |  | 444 | I | By first son |
| Common Stock |  |  |  |  |  |  |  | 444 | I | By second son |
| Common Stock |  |  |  |  |  |  |  | 444 | I | By third son |
| Common Stock |  |  |  |  |  |  |  | 444 | I | By daughter |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (right to buy) | $57.06 | 2026-03-16 |  | A |  | 17563 |  | <sup>(3)</sup> | <sup>(3)</sup> | Common Stock | 17563 | $0 | 17563 | D |  |
| Stock Option (right to buy) | $6.36 |  |  |  |  |  |  | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 316902 |  | 316902 | D |  |
| Stock Option (right to buy) | $12.72 |  |  |  |  |  |  | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 598204 |  | 598204 | D |  |
| Stock Option (right to buy) | $21.31 |  |  |  |  |  |  | <sup>(6)</sup> | <sup>(6)</sup> | Common Stock | 25446 |  | 25446 | D |  |
| Stock Option (right to buy) | $23.50 |  |  |  |  |  |  | <sup>(7)</sup> | <sup>(7)</sup> | Common Stock | 67347 |  | 67347 | D |  |
| Restricted Stock Units | <sup>(8)</sup> |  |  |  |  |  |  | <sup>(9)</sup> | <sup>(9)</sup> | Common Stock | 225000 |  | 225000 | D |  |
| Restricted Stock Units | <sup>(8)</sup> |  |  |  |  |  |  | <sup>(10)</sup> | <sup>(10)</sup> | Common Stock | 150000 |  | 150000 | D |  |

---

### Footnotes:

(1) Represents performance share units earned.

(2) Reflects shares withheld for net settlement to cover the tax liability for the vesting of restricted stock units.

(3) The stock option vests in three equal annual installments beginning on March 16, 2027, and expires on March 16, 2036.

(4) The stock option vested in four installments beginning on June 6, 2021, and expires on June 6, 2027.

(5) The stock option vested in four installments beginning on June 6, 2021, and expires on June 6, 2027

(6) The stock option vests in three equal annual installments beginning on March 15, 2025, and expires on March 15, 2034.

(7) The stock option vests in three equal annual installments beginning on March 17, 2026, and expires on March 17, 2035.

(8) Represents performance-based restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Company's stock.

(9) Conversion of restricted stock units to the Company's common stock will occur on July 5, 2027 assuming the reporting person is still employed by the Company and if the shares of the Company's common stock have achieved certain stock price targets over the course of the performance period.

(10) Conversion of restricted stock units to the Company's common stock will occur on June 4, 2029 assuming the reporting person is still employed by the Company and if the shares of the Company's common stock have achieved certain stock price targets over the course of the performance period.

**Signature:** /s/ Alyson Gregory as Attorney-in-Fact for Todd Gleason  
**Date:** 2026-03-17

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**