Mary Z. Luo
CIK 1611156 · COO, Chief Scientist, Chairman · last filed 2026-03-06
Mary Z. Luo is a COO, Chief Scientist, Chairman who has filed 29 SEC Form 4 insider transactions across 1 company since 2015. The most recent filing shows the insider had shares withheld for taxes covering $327.4K of AMPH on Mar 6, 2026. Across all open-market trades the lifetime net is −$46.1M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $253.2M across reported positions. 62 SEC filings were submitted jointly with Jack Y. Zhang.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
Charts
Trading activity, where the exposure sits, and each trade against the stock price.
AMPH price and trades
Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.
Shares held
Shares owned after each reported transaction on this company (direct holdings as reported).
Open-market buying and selling
by monthDollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.
Exposure by company
latestMost recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.
Filer Profile
RANCHO CUCAMONGA, CA 91730
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| AMPH | COO, Chief Scientist, Chairman | 9,669,569 | $26.19 | $253.25M | -$46.15M | 26 | 2026-03-06 |
Recent Filings
29 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2026-03-06 | AMPH | Tax (F) | −16,402 | -$327.4K | EDGAR |
| 2025-06-16 | AMPH | Exer (M) | +400,000 | $5.21M | EDGAR |
| 2024-11-12 | AMPH | Gift (G) | −500,000 | $0 | EDGAR |
| 2024-01-11 | AMPH | Sell (S) | −262,772 | -$14.34M | EDGAR |
| 2024-01-10 | AMPH | Notice (144) | −131,386 | -$7.17M | EDGAR |
| 2024-01-09 | AMPH | Notice (144) | −86,156 | -$5.05M | EDGAR |
| 2024-01-08 | AMPH | Notice (144) | −133,644 | -$7.88M | EDGAR |
| 2023-03-17 | AMPH | Tax (F) | −22,474 | -$827.9K | EDGAR |
| 2023-03-08 | AMPH | Grant (A) | +231,368 | $0 | EDGAR |
| 2022-05-20 | AMPH | Sell (S) | −217,552 | -$7.40M | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.