H2O America
Ownership
Ownership Structure
Who owns H2O America (HTO)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 87.2% of the shares are freely tradable; institutional investors hold 120.6%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 15.33 | 6,417,733 | -3.6 | 03/31/2026 |
| ATLAS Infrastructure Partners (UK) Ltd | 11.02 | 4,612,035 | +1.8 | 06/30/2026 |
| Wellington Management Company LLP | 4.77 | 1,995,839 | +23.7 | 06/30/2026 |
| Antipodes Partners Limited | 4.20 | 1,759,602 | -21.8 | 06/30/2026 |
| Vanguard Capital Management, LLC | 4.03 | 1,687,253 | +0.0 | 03/31/2026 |
| State Street Corp | 3.42 | 1,431,151 | +5.2 | 03/31/2026 |
| HPM Partners LLC | 3.13 | 1,309,679 | -9.4 | 03/31/2026 |
| Soros Fund Management LLC | 2.94 | 1,228,747 | +0.0 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 2.79 | 1,169,078 | +0.0 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 5.73 | 2,396,379 | +0.0 | 08/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| ATLAS Infrastructure Partners (UK) Ltd. | 10% Owner | 4,615,265 | 291,223,222 $ | Jul 7, 2026 | direct |
| Mattern Megan | CAO, PAO and Controller | 13,631 | 860,116 $ | Jul 30, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Jul 30, 2026 | Mattern Megan | CAO, PAO and Controller | Other | 1,154 | 61.97 | 71,513 |
| Jul 7, 2026 | ATLAS Infrastructure Partners (UK) Ltd. | 10% Owner | Buy | 2,784 | 62.03 | 172,692 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.