ZSTK · Insider Trading
ZeroStack Corp. Common Stock
Every open-market purchase and sale reported by ZSTK officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-21 | Rudy Rong | President | Sell | −1,000 | −$7.57K |
| 2026-07-20 | Dany Vaiman | CFO | A | +250,000 deriv. | — |
| 2026-07-20 | Daniel Reis-Faria | CEO | X | +5,954,743 | +$595 |
| 2026-07-20 | Michael Heinrich | Executive Chairman | Buy | +4,608,575 | +$3.48M |
| 2026-05-07 | Manfred Leventhal | Director | A | +35,000 deriv. | — |
| 2026-05-07 | Edward Woo | Director | A | +35,000 deriv. | — |
| 2026-05-07 | Laurence Zeifman | Director | A | +28,000 deriv. | — |
| 2026-04-02 | Michael Heinrich | Executive Chairman | J | −4,902,220 deriv. | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Daniel Reis-Faria | CEO | 5,954,743 | $18.64M |
| Michael Heinrich | Executive Chairman | 4,608,575 | $14.42M |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the ZSTK quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.