Energy Recovery, Inc. (ERII) Insider Trading
Over the last 3 months, ERII insiders made 1 open-market buy and 5 sales, a net sale of -$2.3M (SEC Form 4). Over the last 6 months, 149 institutions increased and 142 reduced their position (13F).
Insider Activity
Sentiment
6/100
Buys (3m)
1
Sells (3m)
5
Net (3m)
-$2.3M
Insiders buyingFirst buy in 4 quarters
Insider trades by month Buys Sells
Oct
Dec
Feb
Mar
Apr
May
Context3-month price -22.7%Institutions mixed (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| May 15, 2026 | TONDREAU PAMELA L.director | Buy | 20,000 | $8.34 |
| Apr 8, 2026 | Hanstveit Arvedirector | Sell | 2,419 | $10.29 |
| Apr 6, 2026 | Hanstveit Arvedirector | Sell | 165,292 | $10.14 |
| Mar 11, 2026 | Hanstveit Arvedirector | Sell | 25,000 | $10.96 |
| Mar 9, 2026 | Hanstveit Arvedirector | Sell | 11,582 | $10.62 |
| Mar 9, 2026 | Hanstveit Arvedirector | Sell | 38,418 | $10.71 |
| Mar 6, 2026 | Ramanan Natarajanofficer: Chief Technology Officer | Sell | 272 | $10.57 |
| Mar 6, 2026 | Clemente Rodneyofficer: SVP, Water | Sell | 20,568 | $10.61 |
| Mar 4, 2026 | Ramanan Natarajanofficer: Chief Technology Officer | Tax | 2,724 | $10.22 |
| Feb 19, 2026 | Yeung Williamofficer: Chief Legal Officer | Grant | 25,959 | — |
| Feb 19, 2026 | Mancini Michael S.officer: Chief Financial Officer | Grant | 45,626 | — |
| Feb 19, 2026 | Hostetler Matthewofficer: Chief Human Resources Officer | Grant | 25,959 | — |
| Feb 19, 2026 | Ramanan Natarajanofficer: Chief Technology Officer | Grant | 29,106 | — |
| Feb 19, 2026 | Moon David Wdirector, officer: President and CEO | Grant | 81,812 | — |
| Feb 19, 2026 | Clemente Rodneyofficer: SVP, Water | Grant | 45,626 | — |
| Feb 9, 2026 | Yeung Williamofficer: Chief Legal Officer | Sell | 646 | $15.14 |
| Feb 9, 2026 | Yeung Williamofficer: Chief Legal Officer | Sell | 890 | $14.59 |
| Feb 9, 2026 | Clemente Rodneyofficer: SVP, Water | Sell | 724 | $14.59 |
| Feb 3, 2026 | Yeung Williamofficer: Chief Legal Officer | Tax | 1,003 | $14.65 |
| Feb 3, 2026 | Yeung Williamofficer: Chief Legal Officer | Sell | 7,271 | $14.55 |
| Feb 3, 2026 | Moon David Wdirector, officer: President and CEO | Tax | 17,160 | $14.30 |
| Feb 3, 2026 | Mancini Michael S.officer: Chief Financial Officer | Tax | 4,798 | $14.30 |
| Feb 3, 2026 | Hostetler Matthewofficer: Chief Human Resources Officer | Tax | 3,359 | $14.30 |
| Feb 3, 2026 | Clemente Rodneyofficer: SVP, Water | Tax | 8,397 | $14.30 |
| Feb 3, 2026 | Yeung Williamofficer: Chief Legal Officer | Tax | 8,622 | $14.30 |
| Feb 3, 2026 | Clemente Rodneyofficer: SVP, Water | Tax | 694 | $14.65 |
| Feb 3, 2026 | Yeung Williamofficer: Chief Legal Officer | Sell | 729 | $14.46 |
| Dec 8, 2025 | Hanstveit Arvedirector | Sell | 15,000 | $14.97 |
| Oct 27, 2025 | Yeung Williamofficer: Chief Legal Officer | Option | 3,530 | $7.50 |
| Oct 27, 2025 | Yeung Williamofficer: Chief Legal Officer | Option | 5,638 | $10.19 |
Source: ERII SEC Form 4 filings, latest May 15, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their ERII positions over the last 6 months (SEC Form 13F).
Increased
149
New positions
56
Reduced
142
Sold out
59
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| BLACKROCK, INC. | Increased | 6.3M | Feb 12, 2026 |
| BLACKROCK, INC. | Reduced | 6.1M | May 13, 2026 |
| AMERIPRISE FINANCIAL INC | Increased | 5.3M | May 15, 2026 |
| AMERIPRISE FINANCIAL INC | Reduced | 4.6M | Feb 17, 2026 |
| VANGUARD GROUP INC | Increased | 3.9M | Jan 29, 2026 |
| AMUNDI | Increased | 3.7M | May 18, 2026 |
| AMUNDI | Increased | 2.9M | Feb 17, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | New Position | 2.2M | May 15, 2026 |
| FIL LTD | Reduced | 2.0M | Feb 17, 2026 |
| FIL LTD | Reduced | 2.0M | May 15, 2026 |
| LEGAL & GENERAL GROUP PLC | Increased | 1.9M | May 8, 2026 |
| STATE STREET CORP | Increased | 1.8M | May 15, 2026 |
| STATE STREET CORP | Increased | 1.8M | Feb 13, 2026 |
| LEGAL & GENERAL GROUP PLC | Increased | 1.3M | Feb 9, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | Increased | 1.3M | May 15, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.