[Form 4] Energy Recovery, Inc. Insider Trading Activity

Rhea-AI Filing Summary

William Yeung, Chief Legal Officer of Energy Recovery, Inc. (ERII), reported option exercise and share sales on 09/18/2025. He exercised 15,454 employee stock options with an exercise price of $8.95 per share and immediately sold 15,454 shares under a Rule 10b5-1 trading plan at a weighted average sale price of $15.086 per share. Following these transactions, Mr. Yeung beneficially owned 97,369 shares directly and 5,568 indirectly through his spouse. The filing notes the options became fully vested on 06/20/2020 and the reported transactions were effected pursuant to a 10b5-1 plan.

Positive

• Transactions executed under a Rule 10b5-1 plan, indicating pre-planned, systematic trading
• Sale price ($15.086 weighted average) exceeded the option exercise price ($8.95), as reported

Negative

• Direct beneficial ownership declined from 112,823 shares immediately after exercise to 97,369 shares after the sale
• Insider sold 15,454 shares, indicating executive liquidity rather than additional share accumulation

Insights

Financial Analyst

TL;DR: Routine option exercise and planned sale by an officer, with sale price above exercise price.

This filing documents a common liquidity event where an executive exercised vested employee stock options and sold the resulting shares under a pre-established Rule 10b5-1 plan. The exercise price was $8.95 and the weighted average sale price was $15.086, indicating the sales occurred at a higher market price than the option strike. Post-transaction direct beneficial ownership is reported at 97,369 shares, with an additional 5,568 held indirectly by a spouse. For investors, this is a disclosure of insider liquidity rather than an operational update.

Corporate Governance Expert

TL;DR: Transactions were executed under a documented 10b5-1 plan and adhere to routine disclosure practices.

The reporting person is identified as the Chief Legal Officer and checked the box indicating transactions were made pursuant to a Rule 10b5-1 plan. The Form 4 includes an explanation of vesting schedule and confirms the options were fully vested as of 06/20/2020. Signature and filing details are provided, consistent with standard Section 16 reporting. This appears to be a compliant, pre-planned insider transaction with no additional governance issues disclosed in the filing.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

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

X

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^*

Yeung William

(Last) (First) (Middle)

C/O ENERGY RECOVERY, INC.

1717 DOOLITTLE DRIVE

(Street)

SAN LEANDRO CA 94577

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Energy Recovery, Inc. [ ERII ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/18/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/18/2025		M		15,454	A	$8.95	112,823	D
Common Stock	09/18/2025		S		15,454(1)	D	$15.086(2)	97,369	D
Common Stock								5,568	I	Spouse

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	$8.95	09/18/2025		M			15,454	(3)	06/19/2026	Common Stock	15,454	$8.95	0	D

Explanation of Responses:

1. These transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

2. This amount represents the weighted average sales price of multiple trades ranging from $15 to $15.21 per share. The reporting person undertakes to provide the SEC Staff, Energy Recovery, Inc. or a shareholder of Energy Recovery, Inc. full information about the number of shares sold at each separate price upon request.

3. 25% of the shares became vested and exercisable on the 1st anniversary of the vesting start date of 06/20/2016; Thereafter, the remaining 75%, will vest and become exercisable 1/36th per month. The options become fully vested and exercisable on 06/20/2020.

Remarks:

	/s/ William Yeung	09/22/2025
	** Signature of Reporting Person	Date
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.

FAQ

What did William Yeung (ERII) report on Form 4?

He reported exercising 15,454 employee stock options at $8.95 per share and selling 15,454 shares under a Rule 10b5-1 plan at a weighted average price of $15.086 on 09/18/2025.

How many ERII shares does William Yeung own after the transactions?

The filing reports 97,369 shares owned directly and 5,568 shares owned indirectly by his spouse.

Were the option exercises and sales pre-planned?

Yes. The form indicates the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

What were the option vesting details disclosed?

The filing states 25% vested on the first anniversary of 06/20/2016 and the remaining vested monthly thereafter, with options fully vested on 06/20/2020.

When was the Form 4 signed and filed?

The signature on the Form 4 is dated 09/22/2025.