As of September 09, 2026, the three largest insider holders of ERII are Ole Peter Lorentzen (TenPercentOwner, 5.16Mn shares), Arve Hanstveit (Director, 400.60K shares), Robert Yu Lang Mao (President And Ceo, 248.94K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Ole Peter Lorentzen | TenPercentOwner | 0 | 5,155,239 | 5,155,239 | 75.6% | 17 Sep, 2021 |
| 2 | Arve Hanstveit | Director | 400,603 | 0 | 400,603 | 5.9% | 05 Jun, 2026 |
| 3 | Robert Yu Lang Mao | President And Ceo | 248,935 | 0 | 248,935 | 3.7% | 24 May, 2024 |
| 4 | David W Moon | President And Ceo | 233,069 | 0 | 233,069 | 3.4% | 19 Feb, 2026 |
| 5 | Farshad Ghasripoor | Chief Technology Officer | 52,860 | 70,230 | 123,090 | 1.8% | 05 Feb, 2025 |
| 6 | Rodney Clemente | Svp, Water | 108,301 | 0 | 108,301 | 1.6% | 29 Jul, 2026 |
| 7 | William Yeung | Chief Legal Officer | 99,291 | 0 | 99,291 | 1.5% | 29 Jul, 2026 |
| 8 | Michael S. Mancini | Chief Financial Officer | 75,051 | 0 | 75,051 | 1.1% | 19 Feb, 2026 |
| 9 | Alexander J Buehler | Interim President And Ceo | 66,755 | 0 | 66,755 | 1.0% | 17 Jun, 2026 |
| 10 | Pamela L. Tondreau | Director | 60,844 | 0 | 60,844 | 0.9% | 05 Jun, 2026 |
| 11 | Natarajan Ramanan | Chief Technology Officer | 52,565 | 0 | 52,565 | 0.8% | 06 Mar, 2026 |
| 12 | Joan Kai Chow | Director | 52,116 | 0 | 52,116 | 0.8% | 05 Jun, 2026 |
| 13 | Matthew Hostetler | Chief Human Resources Officer | 46,556 | 0 | 46,556 | 0.7% | 19 Feb, 2026 |
| 14 | Joshua Ballard | Chief Financial Officer | 40,376 | 0 | 40,376 | 0.6% | 30 May, 2024 |
| 15 | Aidan Ryan | Interim Cfo | 34,133 | 0 | 34,133 | 0.5% | 24 Jun, 2026 |
| 16 | John Joseph Mitchell | Director | 16,797 | 0 | 16,797 | 0.2% | 21 Jul, 2026 |
| 17 | Lisa A Pollina | Director | 4,007 | 0 | 4,007 | 0.1% | 13 Jun, 2023 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 27 Jul, 2026 | William Yeung | Chief Legal Officer | Disposed F | 2,828 | $8.42 | $23.81K | 101,339 | Direct |
| 27 Jul, 2026 | Rodney Clemente | Svp, Water | Disposed F | 2,320 | $8.42 | $19.53K | 113,688 | Direct |
| 28 Jul, 2026 | Rodney Clemente | Svp, Water | Disposed S | 5,387 | $8.56 | $46.11K | 108,301 | Direct |
| 28 Jul, 2026 | William Yeung | Chief Legal Officer | Disposed S | 2,048 | $8.56 | $17.53K | 99,291 | Direct |
| 09 Jul, 2026 | John Joseph Mitchell | Director | Acquired A | 16,797 | $0.00 | $0 | 16,797 | Direct |
| 06 May, 2026 | Aidan Ryan | Interim Cfo | Acquired A | 18,518 | $11.61 | $214.99K | 34,133 | Direct |
| 15 Jun, 2026 | Colin R Sabol | Director | Acquired P | 11,180 | $8.88 | $99.27K | 55,671 | Direct |
| 15 Jun, 2026 | Alexander J Buehler | Interim President And Ceo | Acquired M | 15,327 | $8.60 | $131.81K | 81,655 | Direct |
| 15 Jun, 2026 | Alexander J Buehler | Interim President And Ceo | Disposed S | 14,900 | $8.71 | $129.78K | 66,755 | Direct |
| 15 Jun, 2026 | Alexander J Buehler | Interim President And Ceo | Disposed M | 15,327 | $8.60 | $131.81K | 0 | Direct |
| 04 Jun, 2026 | Colin R Sabol | Director | Acquired A | 18,094 | $8.29 | $150.00K | 44,491 | Direct |
| 04 Jun, 2026 | Pamela L. Tondreau | Director | Acquired A | 22,316 | $8.29 | $185.00K | 60,844 | Direct |
| 04 Jun, 2026 | Joan Kai Chow | Director | Acquired A | 18,094 | $8.29 | $150.00K | 52,116 | Direct |
| 04 Jun, 2026 | Arve Hanstveit | Director | Acquired A | 18,094 | $8.29 | $150.00K | 400,603 | Direct |
| 13 May, 2026 | Pamela L. Tondreau | Director | Acquired P | 20,000 | $8.34 | $166.84K | 37,362 | Indirect |
| 06 Apr, 2026 | Arve Hanstveit | Director | Disposed S | 2,419 | $10.29 | $24.89K | 382,509 | Direct |
| 02 Apr, 2026 | Arve Hanstveit | Director | Disposed S | 165,292 | $10.14 | $1.68Mn | 384,928 | Direct |
| 10 Mar, 2026 | Arve Hanstveit | Director | Disposed S | 25,000 | $10.96 | $273.98K | 550,220 | Direct |
| 05 Mar, 2026 | Arve Hanstveit | Director | Disposed S | 38,418 | $10.71 | $411.46K | 586,802 | Direct |
| 06 Mar, 2026 | Arve Hanstveit | Director | Disposed S | 11,582 | $10.62 | $122.94K | 575,220 | Direct |