California Water Service Group (CWT) Ownership
CWT ownership summary
as of October 18, 2026- Institutions
- 98.6% of shares outstanding
- Insiders
- 0.64% of shares outstanding
- Shares outstanding
- 61.8M
- Float
- 61.3M shares available to trade
- Short interest
- 5.62% 2.5M shares short
- Days to cover
- 4.96 short interest up 2.3% vs prior month
- Institutions 98.62%
- Insiders 0.64%
- Other investors 0.74%
CWT top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 17.39% | 10.8M | $498.5M | +446,943 (+4.3%) | June 30, 2026 |
| 2 | Vanguard Portfolio Management, LLC | 7.08% | 4.4M | $203.0M | +89,998 (+2.1%) | June 30, 2026 |
| 3 | T. Rowe Price Investment Management,Inc. | 5.69% | 3.5M | $163.0M | +98,811 (+2.9%) | June 30, 2026 |
| 4 | Amundi | 5.64% | 3.5M | $161.6M | +15,862 (+0.5%) | June 30, 2026 |
| 5 | State Street Corp | 5.28% | 3.3M | $151.4M | +164,191 (+5.3%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 4.35% | 2.7M | $124.7M | +25,438 (+1.0%) | June 30, 2026 |
| 7 | ATLAS Infrastructure Partners (UK) Ltd | 3.21% | 2.0M | $92.0M | +2.0M (0.0%) | June 30, 2026 |
| 8 | Geode Capital Management, LLC | 2.52% | 1.6M | $72.1M | +79,986 (+5.4%) | June 30, 2026 |
| 9 | First Trust Advisors L.P. | 2.10% | 1.3M | $60.3M | −54,110 (−4.0%) | June 30, 2026 |
| 10 | FMR Inc | 2.07% | 1.3M | $59.4M | −108,608 (−7.8%) | June 30, 2026 |
| 11 | Dimensional Fund Advisors, Inc. | 1.90% | 1.2M | $54.5M | +16,555 (+1.4%) | June 30, 2026 |
| 12 | Mariner Value Strategies, LLC | 1.77% | 1.1M | $50.8M | −507,671 (−31.7%) | June 30, 2026 |
| 13 | Amvescap Plc. | 1.58% | 975K | $45.2M | −27,457 (−2.7%) | June 30, 2026 |
| 14 | Morgan Stanley - Brokerage Accounts | 1.53% | 948K | $43.9M | −170,593 (−15.2%) | June 30, 2026 |
| 15 | Legal & General Group PLC | 1.31% | 808K | $37.4M | +29,968 (+3.9%) | June 30, 2026 |
| 16 | Antipodes Partners Limited | 1.22% | 753K | $34.9M | +753,386 (0.0%) | June 30, 2026 |
| 17 | Delaware Management Holdings Inc | 1.21% | 747K | $34.6M | +747,216 (0.0%) | June 30, 2026 |
| 18 | Charles Schwab Investment Management Inc | 1.17% | 725K | $33.6M | −3,166 (−0.4%) | June 30, 2026 |
| 19 | Northern Trust Corp | 1.15% | 709K | $32.9M | +71,460 (+11.2%) | June 30, 2026 |
| 20 | AQR Capital Management LLC | 1.10% | 682K | $31.6M | +512,060 (+301.7%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 14 holders added 5.0M shares and 6 cut 872K.
CWT top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | iShares Core S&P Small-Cap ETF | 5.94% | 3.7M | $170.2M | +849 (+0.0%) | September 30, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 3.08% | 1.9M | $88.4M | −3,867 (−0.2%) | August 31, 2026 |
| 3 | iShares Russell 2000 ETF | 2.60% | 1.6M | $74.5M | −18,496 (−1.1%) | September 30, 2026 |
| 4 | Vanguard Small Cap Index | 2.25% | 1.4M | $64.5M | +16,133 (+1.2%) | September 30, 2026 |
| 5 | Fidelity Small Cap Value Fund | 2.07% | 1.3M | $59.4M | +129,200 (+11.2%) | July 31, 2026 |
| 6 | Amundi KBI Aqua C | 1.79% | 1.1M | $51.3M | — | August 31, 2026 |
| 7 | KBI Water A GBP | 1.46% | 903K | $41.9M | +41,191 (+4.8%) | September 30, 2026 |
| 8 | T. Rowe Price Small-Cap Value | 1.46% | 901K | $41.8M | — | September 30, 2026 |
| 9 | iShares Global Water ETF USD Dist | 1.45% | 899K | $41.7M | — | September 30, 2026 |
| 10 | Vanguard MStar Small Cap Growth Indx Inv | 1.25% | 775K | $35.9M | −13,776 (−1.7%) | September 30, 2026 |
| 11 | T. Rowe Price Small-Cap Stock | 1.23% | 761K | $35.3M | −4,375 (−0.6%) | September 30, 2026 |
| 12 | First Trust Value Line® Dividend ETF | 1.11% | 686K | $31.8M | — | September 30, 2026 |
| 13 | Fidelity Small Cap Index | 1.08% | 666K | $30.9M | +5,613 (+0.9%) | July 31, 2026 |
| 14 | Nomura Small Cap Value A | 0.95% | 586K | $27.2M | — | August 31, 2026 |
| 15 | iShares Russell 2000 Value ETF | 0.94% | 584K | $27.1M | +884 (+0.2%) | September 30, 2026 |
| 16 | State Street SPDR Port S&P 600 Sm CpETF | 0.91% | 561K | $26.0M | — | September 30, 2026 |
| 17 | State Street® SPDR® S&P® Dividend ETF | 0.84% | 520K | $24.1M | — | September 30, 2026 |
| 18 | Triodos Pioneer Impact EUR R Acc | 0.80% | 493K | $22.9M | — | September 30, 2026 |
| 19 | First Trust Water ETF | 0.73% | 452K | $20.9M | — | September 30, 2026 |
| 20 | Vanguard Tax-Managed Small Cap Adm | 0.72% | 448K | $20.8M | — | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
CWT insider transactions
latest 3| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-20 | Michael B Luu | Sell | $44.53 | 740 | $32,952 |
| 2026-03-20 | Michael S Mares Jr | Sell | $44.00 | 3,892 | $171,248 |
| 2025-06-12 | Lester A Snow | Sell | $46.51 | 1,200 | $55,812 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
CWT shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns CWT
Institutional investors own 98.6% of California Water Service's shares and insiders 0.64%. The largest holder is BlackRock Inc with 17.39% of the shares (10.8M), as of June 30, 2026. Among the top 20 institutions, 14 added shares and 6 reduced their stake in the latest filings. Short interest is 5.62% of the float, or 4.96 days of average trading volume. The share count rose 24.8% since 2014.
Related: CWT analyst forecast, CWT key metrics, CWT dividend history. See the CWT stock overview for the latest quote and news.
CWT ownership FAQ
Who owns the most California Water Service stock?
The largest shareholders of California Water Service are BlackRock Inc (17.39%), Vanguard Portfolio Management, LLC (7.08%), T. Rowe Price Investment Management,Inc. (5.69%), Amundi (5.64%), State Street Corp (5.28%).
What percentage of California Water Service is owned by institutions?
Institutions hold 98.6% of California Water Service's shares outstanding; insiders hold 0.64%.
Which funds own California Water Service?
The largest fund holders of California Water Service are iShares Core S&P Small-Cap ETF (5.94%), Vanguard MStar Total Stk Mkt Idx Invest (3.08%), iShares Russell 2000 ETF (2.60%), Vanguard Small Cap Index (2.25%), Fidelity Small Cap Value Fund (2.07%).
What is California Water Service's short interest?
2.5M shares of California Water Service were sold short, 5.62% of the float; at the average daily volume it would take 4.96 days to cover.
Are insiders buying or selling California Water Service?
Of the latest 3 reported insider transactions in California Water Service (since June 12, 2025), 0 were purchases and 3 were sales.
How many shares of California Water Service are outstanding?
California Water Service has 61.8M shares outstanding, of which 61.3M are in the public float.