William Yeung - 23 Oct 2025 Form 4 Insider Report for Energy Recovery, Inc. (ERII)

Signature
/s/ William Yeung
Issuer symbol
ERII
Transactions as of
23 Oct 2025
Net transactions value
-$226,799
Form type
4
Filing time
27 Oct 2025, 17:28:52 UTC
Previous filing
22 Oct 2025
Next filing
03 Feb 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Yeung William Chief Legal Officer C/O ENERGY RECOVERY, INC., 1717 DOOLITTLE DRIVE, SAN LEANDRO /s/ William Yeung 27 Oct 2025 0001677876

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ERII Common Stock Options Exercise $26,475 +3,530 +3.6% $7.50 100,899 23 Oct 2025 Direct
transaction ERII Common Stock Sale $61,775 -3,530 -3.5% $17.50 97,369 23 Oct 2025 Direct F1
transaction ERII Common Stock Options Exercise $57,451 +5,638 +5.8% $10.19 103,007 24 Oct 2025 Direct
transaction ERII Common Stock Sale $101,484 -5,638 -5.5% $18.00 97,369 24 Oct 2025 Direct F1
transaction ERII Common Stock Options Exercise $26,475 +3,530 +3.6% $7.50 100,899 24 Oct 2025 Direct
transaction ERII Common Stock Sale $63,540 -3,530 -3.5% $18.00 97,369 24 Oct 2025 Direct F1
holding ERII Common Stock 5,568 23 Oct 2025 Spouse

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction ERII Employee Stock Option (Right to Buy) Options Exercise $26,475 -3,530 -17% $7.50 17,650 23 Oct 2025 Common Stock 3,530 $7.50 Direct F2
transaction ERII Employee Stock Option (Right to Buy) Options Exercise $57,451 -5,638 -26% $10.19 16,229 24 Oct 2025 Common Stock 5,638 $10.19 Direct F3
transaction ERII Employee Stock Option (Right to Buy) Options Exercise $26,475 -3,530 -20% $7.50 14,120 24 Oct 2025 Common Stock 3,530 $7.50 Direct F2
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id Content
F1 These transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.
F2 This employee stock option was granted on February 1, 2018. 25% of the shares fully vest on the 1st anniversary of the vesting start date; thereafter, the remaining 75%, vest 1/36th per month.
F3 25% of these options fully vest on the 1st anniversary of the vesting start date of 02/02/2017; thereafter, the remaining 75% vest 1/36th per month.