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 | 16.98 | 7,106,413 | +10.7 | 06/30/2026 |
| 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 | 3.76 | 1,574,377 | -6.7 | 06/30/2026 |
| State Street Corp | 3.71 | 1,554,683 | +8.6 | 06/30/2026 |
| HPM Partners LLC | 3.12 | 1,307,227 | -0.2 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 3.02 | 1,263,898 | +8.1 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 5.18 | 2,167,716 | +0.0 | 09/30/2026 |
| Vanguard MStar Total Stk Mkt Idx Invest | 3.04 | 1,273,791 | +19.3 | 09/30/2026 |
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 | 275,531,321 $ | Jul 7, 2026 | direct |
| Mattern Megan | CAO, PAO and Controller | 13,631 | 813,771 $ | 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: October 30, 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.