MONOLITHIC POWER SYSTEMS, INC. Insider Trading Activity
Every SEC Form 4 insider transaction reported for MONOLITHIC POWER SYSTEMS, INC. (MPWR), sourced directly from SEC EDGAR and updated as new filings are accepted.
By Trabud · Insider-trading data from SEC EDGAR
Latest filing:
Compiled automatically from SEC EDGAR Form 4 filings and refreshed daily. Figures count purchases (code P) and sales (code S) only — not grants, option exercises, or gifts. How this page is built. Not investment advice.
Quick Answer
Are MPWR insiders buying or selling?
In the last 12 months, MONOLITHIC POWER SYSTEMS, INC. insiders reported 0 open-market purchases ($0) and 56 sales ($729.1M) — net selling of $729.1M. Since January 2018, Trabud has recorded 671 Form 4 filings for MPWR: 0 buys ($0) and 671 sells ($2.2B).
Source: SEC EDGAR Form 4
What stands out
- No MONOLITHIC POWER SYSTEMS, INC. insider made an open-market purchase in the last 12 months; the 56 reported open-market sales totaled $729.1M.
Key Statistics (January 2018 – Sep 30, 2026)
Total Form 4 filings
671
SEC EDGAR
Insider filers
13
Insider buys (0)
$0
Insider sells (671)
$2.2B
Insider sentiment
Net sellingNet insider flow of $2.2B in net selling since January 2018, and $729.1M in net selling over the last 12 months.
Recent MPWR insider transactions
| Date | Insider | Role | Type | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Sep 30, 2026 | Michael Hsing | CEO | Sale | 30.0K | $1344.97 | $40.3M | SEC ↗ |
| Aug 26, 2026 | Robert W Dean II | Interim CFO | Sale | 32 | $1297.72 | $41.5K | SEC ↗ |
| Aug 25, 2026 | Kuo Wei Herbert Chang | Director | Sale | 50 | $1281.57 | $64.1K | SEC ↗ |
| Aug 20, 2026 | Robert W Dean II | Interim CFO | Sale | 6 | $1413.64 | $8.5K | SEC ↗ |
| Aug 13, 2026 | Kuo Wei Herbert Chang | Director | Sale | 50 | $1420.00 | $71.0K | SEC ↗ |
| Aug 6, 2026 | Robert W Dean II | Interim CFO | Sale | 105 | $1344.27 | $141.1K | SEC ↗ |
| Aug 5, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 30 | $1343.94 | $40.3K | SEC ↗ |
| Jul 17, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 15.0K | $1349.73 | $20.2M | SEC ↗ |
| Jul 6, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 30 | $1351.61 | $40.5K | SEC ↗ |
| Jun 3, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 30 | $1533.95 | $46.0K | SEC ↗ |
| May 29, 2026 | Saria Tseng | EVP & General Counsel | Sale | 7.6K | $1700.00 | $12.9M | SEC ↗ |
| May 28, 2026 | Robert W Dean II | Interim CFO | Sale | 22 | $1649.56 | $36.3K | SEC ↗ |
| May 27, 2026 | Jeff Zhou | Director | Sale | 486 | $1680.00 | $816.5K | SEC ↗ |
| May 27, 2026 | Saria Tseng | EVP & General Counsel | Sale | 5.0K | $1586.43 | $7.9M | SEC ↗ |
| May 21, 2026 | Michael Hsing | CEO | Sale | 40.0K | $1482.75 | $59.3M | SEC ↗ |
| May 20, 2026 | Robert W Dean II | Interim CFO | Sale | 4 | $1563.28 | $6.3K | SEC ↗ |
| May 19, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 12.0K | $1561.40 | $18.7M | SEC ↗ |
| May 8, 2026 | Eugen J Elmiger | Director | Sale | 12.0K | $1584.96 | $19.0M | SEC ↗ |
| May 8, 2026 | Deming Xiao | EVP, Global Operations | Sale | 30.0K | $1654.55 | $49.6M | SEC ↗ |
| May 8, 2026 | Eileen Wynne | Director | Sale | 335 | $1582.68 | $530.2K | SEC ↗ |
| May 6, 2026 | Jeff Zhou | Director | Sale | 1.5K | $1607.85 | $2.4M | SEC ↗ |
| May 6, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 380 | $1583.81 | $601.8K | SEC ↗ |
| May 6, 2026 | Maurice Sciammas | EVP, WW Sales & Marketing | Sale | 30 | $1588.73 | $47.7K | SEC ↗ |
| Apr 10, 2026 | Saria Tseng | EVP & General Counsel | Sale | 9.0K | $1305.22 | $11.7M | SEC ↗ |
| Apr 8, 2026 | Saria Tseng | EVP & General Counsel | Sale | 7.6K | $1167.95 | $8.9M | SEC ↗ |
Showing the 25 most recent of 671 Form 4 filings for MONOLITHIC POWER SYSTEMS, INC..
Most active MPWR insiders
- Theodore Blegen128 filings
- Maurice Sciammas115 filings
- Michael Hsing109 filings
- Saria Tseng107 filings
- Deming Xiao105 filings
Ask anything about MPWR insider activity
Use Trabud's AI agent to query MONOLITHIC POWER SYSTEMS, INC.'s Form 4 history in plain English — "Show me MPWR CEO purchases this year" or compare it against any other ticker.
Open the AI agentMPWR insider trading FAQ
Are MONOLITHIC POWER SYSTEMS, INC. insiders buying or selling?
In the last 12 months, MONOLITHIC POWER SYSTEMS, INC. insiders reported 0 open-market purchases ($0) and 56 sales ($729.1M) — net selling of $729.1M. Since January 2018, Trabud has recorded 671 Form 4 filings for MPWR: 0 buys ($0) and 671 sells ($2.2B). Over the full record that is net selling of $2.2B.
How many insiders trade MPWR stock?
13 distinct insider filers — officers, directors, 10%+ owners, and investment groups filing jointly — have reported Form 4 transactions for MONOLITHIC POWER SYSTEMS, INC.. The most recent filing was accepted on Sep 30, 2026.
Where does Trabud get MPWR insider trading data?
All MPWR insider trading data comes directly from official SEC EDGAR Form 4 filings, which corporate insiders must submit within two business days of a transaction under Section 16(a) of the Securities Exchange Act of 1934.