ZeroStack Corp. (ZSTK) Ownership
ZSTK ownership summary
as of October 18, 2026- Institutions
- 0.4% of shares outstanding
- Insiders
- 83.60% of shares outstanding
- Shares outstanding
- 21.8M
- Float
- 6.1M shares available to trade
- Short interest
- 0.45% 97K shares short
- Days to cover
- 0.81 short interest down 22.0% vs prior month
- Institutions 0.40%
- Insiders 83.60%
- Other investors 16.00%
ZSTK top institutional holders
15 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard Capital Management, LLC | 0.12% | 25K | $101,760 | — | June 30, 2026 |
| 2 | Geode Capital Management, LLC | 0.10% | 21K | $83,976 | −4,327 (−17.1%) | June 30, 2026 |
| 3 | Vanguard Fiduciary Trust Co | 0.06% | 13K | $50,592 | — | June 30, 2026 |
| 4 | Tower Research Capital LLC | 0.01% | 1,730 | $6,920 | +1,730 (0.0%) | June 30, 2026 |
| 5 | UBS Group AG | <0.01% | 440 | $1,760 | −226 (−33.9%) | June 30, 2026 |
| 6 | Mercer Global Advisors Inc. | <0.01% | 25 | $100 | +25 (0.0%) | June 30, 2026 |
| 7 | Royal Bank of Canada | <0.01% | 12 | $48 | — | June 30, 2026 |
| 8 | Advisor Group Holdings, Inc. | <0.01% | 12 | $48 | — | June 30, 2026 |
| 9 | Morgan Stanley - Brokerage Accounts | 0.00% | 7 | $28 | −166 (−96.0%) | June 30, 2026 |
| 10 | Barclays PLC | 0.00% | 3 | $12 | +3 (0.0%) | June 30, 2026 |
| 11 | Citigroup Inc | 0.00% | 1 | $4 | +1 (0.0%) | June 30, 2026 |
| 12 | KEY Financial, INC. | 0.00% | 1 | $4 | — | June 30, 2026 |
| 13 | Sound Income Strategies | 0.00% | — | — | −12 (−100.0%) | June 30, 2026 |
| 14 | Creekmur Asset Management LLC | 0.00% | — | — | −1 (−100.0%) | March 31, 2026 |
| 15 | Bank of America Corp | 0.00% | — | — | −7 (−100.0%) | March 31, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 15, 4 holders added 1,759 shares and 6 cut 4,739.
ZSTK top mutual fund and ETF holders
4 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Fidelity Extended Market Index | 0.06% | 13K | $53,056 | −71 (−0.5%) | August 31, 2026 |
| 2 | Fidelity Series Total Market Index | 0.01% | 2,282 | $9,128 | — | August 31, 2026 |
| 3 | Fidelity Total Market Index | 0.01% | 1,489 | $5,956 | — | August 31, 2026 |
| 4 | Fidelity Nasdaq Composite Index | <0.01% | 133 | $532 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
ZSTK shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns ZSTK
Institutional investors own 0.4% of ZeroStack's shares and insiders 83.60%. The largest holder is Vanguard Capital Management, LLC with 0.12% of the shares (25K), as of June 30, 2026. Among the top 15 institutions, 4 added shares and 6 reduced their stake in the latest filings. Short interest is 0.45% of the float, or 0.81 days of average trading volume. The share count fell 72.8% since 2019.
Related: ZSTK analyst forecast, ZSTK key metrics. See the ZSTK stock overview for the latest quote and news.
ZSTK ownership FAQ
Who owns the most ZeroStack stock?
The largest shareholders of ZeroStack are Vanguard Capital Management, LLC (0.12%), Geode Capital Management, LLC (0.10%), Vanguard Fiduciary Trust Co (0.06%), Tower Research Capital LLC (0.01%), UBS Group AG (<0.01%).
What percentage of ZeroStack is owned by institutions?
Institutions hold 0.4% of ZeroStack's shares outstanding; insiders hold 83.60%.
Which funds own ZeroStack?
The largest fund holders of ZeroStack are Fidelity Extended Market Index (0.06%), Fidelity Series Total Market Index (0.01%), Fidelity Total Market Index (0.01%), Fidelity Nasdaq Composite Index (<0.01%).
What is ZeroStack's short interest?
97K shares of ZeroStack were sold short, 0.45% of the float; at the average daily volume it would take 0.81 days to cover.
How many shares of ZeroStack are outstanding?
ZeroStack has 21.8M shares outstanding, of which 6.1M are in the public float.