Transactions
74
Insider / MONOLITHIC POWER SYSTEMS INC
Tseng Saria
EVP & General Counsel at MONOLITHIC POWER SYSTEMS INC
- Company
- MONOLITHIC POWER SYSTEMS INC
- Ticker
- MPWR
- First filing on record
- October 17, 2025
- Latest trade on record
- August 31, 2026
- SEC filings
- EDGAR ↗
Tseng Saria, EVP & General Counsel at MONOLITHIC POWER SYSTEMS INC, has disclosed 74 transactions in MPWR since October 17, 2025: 0 purchases (0 open-market buys) and 67 sales, worth about $210.7M at the reported prices. The latest was filed September 2, 2026, 2 days after the trade; 4 filings were late against the 2-business-day Form 4 deadline.
Open-market buys
0
Sales
67
Avg. disclosure lag
2.4d
Trading in charts
Trade timeline
When does this person trade, how big, and in which direction? Every trade in the last 12 months.
Bought (above the line)Sold (below the line)Other transaction
In the last 12 months Tseng Saria made no purchases and 64 sales worth $194M, plus 7 other transactions. Dot size is the dollar amount.
Portfolio mix
Which stocks does this person trade most? Tile size is dollars traded, all time on record.
Tseng Saria has traded 1 stock on record; the largest by dollars is MPWR.
Reporting lag
Does this person report on time? One bar per filing against the Form 4 deadline.
On timeLate
2 of 16 filings on record were reported after the Form 4 deadline (two business days, counted here as 4 calendar days).
What kind of transactions
Most Form 4 rows are pay arriving or tax being withheld, not a decision to buy or sell. Only code P is an open-market purchase and code S an open-market sale. What each code means: Form 4 transaction codes.
| Code | Meaning | Rows | Shares | Value |
|---|---|---|---|---|
| S | Open-market sale | 66 | 137,253 | $150.9M |
| G | Gift | 5 | 6,200 | — |
| A | Grant or award | 2 | 192,690 | — |
| F | Shares withheld for tax | 1 | 54,543 | $59.8M |
| Year | Rows | Bought | Sold |
|---|---|---|---|
| 2026 | 38 | 0 | 34 · $95.7M |
| 2025 | 36 | 0 | 33 · $115.0M |
Transactions
| Security | Side | Trade date | Disclosed | Lag | Shares | Price | Value | Flags | Source | Share |
|---|---|---|---|---|---|---|---|---|---|---|
| MPWR | Other G | August 31, 2026 | September 2, 2026 | 2d | 2,000 | — | — | indirect | Form 4 ↗ | |
| MPWR | Other G | August 31, 2026 | September 2, 2026 | 2d | 2,000 | — | — | Form 4 ↗ | ||
| MPWR | Sell S | May 27, 2026 | May 29, 2026 | 2d | 7,565 | $1,700 | $12.9M | Form 4 ↗ | ||
| MPWR | Sell S | May 22, 2026 | May 27, 2026 | 5d | 5,000 | $1,586 | $7.9M | late | Form 4 ↗ | |
| MPWR | Other G | May 22, 2026 | May 27, 2026 | 5d | 200 | — | — | late | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 120 | $1,322 | $159K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 840 | $1,319 | $1.1M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 4,244 | $1,313 | $5.6M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 1,279 | $1,308 | $1.7M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 800 | $1,303 | $1.0M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 400 | $1,292 | $517K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 120 | $1,287 | $154K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 240 | $1,280 | $307K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 360 | $1,270 | $457K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 8, 2026 | April 10, 2026 | 2d | 560 | $1,266 | $709K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 1,396 | $1,180 | $1.6M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 1,680 | $1,176 | $2.0M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 2,036 | $1,170 | $2.4M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 684 | $1,166 | $797K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 560 | $1,160 | $649K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 480 | $1,149 | $552K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 556 | $1,144 | $636K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 6, 2026 | April 8, 2026 | 2d | 244 | $1,140 | $278K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 1, 2026 | April 3, 2026 | 2d | 292 | $1,137 | $332K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 1, 2026 | April 3, 2026 | 2d | 188 | $1,136 | $214K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 1, 2026 | April 3, 2026 | 2d | 160 | $1,134 | $181K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 1, 2026 | April 3, 2026 | 2d | 184 | $1,132 | $208K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | April 1, 2026 | April 3, 2026 | 2d | 576 | $1,131 | $652K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 80 | $1,041 | $83K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 166 | $1,036 | $172K | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 2,440 | $1,029 | $2.5M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 2,200 | $1,023 | $2.3M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 3,194 | $1,017 | $3.2M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 3,360 | $1,010 | $3.4M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 9,080 | $1,005 | $9.1M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | March 30, 2026 | April 1, 2026 | 2d | 5,154 | $1,001 | $5.2M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | February 6, 2026 | February 10, 2026 | 4d | 22,875 | $1,171 | $26.8M | Form 4 ↗ | ||
| MPWR | Other A | February 3, 2026 | February 5, 2026 | 2d | 57,170 | — | — | Form 4 ↗ | ||
| MPWR | Other G | December 24, 2025 | December 30, 2025 | 6d | 1,000 | — | — | lateindirect | Form 4 ↗ | |
| MPWR | Other G | December 24, 2025 | December 30, 2025 | 6d | 1,000 | — | — | late | Form 4 ↗ | |
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 680 | $930 | $633K | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 2,238 | $929 | $2.1M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 984 | $929 | $914K | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 1,845 | $927 | $1.7M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 10,360 | $926 | $9.6M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 1,126 | $926 | $1.0M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 1,327 | $924 | $1.2M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 1,200 | $924 | $1.1M | Form 4 ↗ | ||
| MPWR | Sell S | November 26, 2025 | November 28, 2025 | 2d | 240 | $923 | $221K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 240 | $912 | $219K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 324 | $912 | $295K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 359 | $910 | $327K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 556 | $909 | $506K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 888 | $908 | $807K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 10,200 | $907 | $9.3M | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 272 | $906 | $247K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 160 | $905 | $145K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 200 | $904 | $181K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 160 | $904 | $145K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 120 | $902 | $108K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 880 | $902 | $793K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 346 | $900 | $312K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 320 | $899 | $288K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 145 | $898 | $130K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 754 | $898 | $677K | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 2,066 | $896 | $1.9M | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 1,625 | $896 | $1.5M | Form 4 ↗ | ||
| MPWR | Sell S | November 25, 2025 | November 28, 2025 | 3d | 385 | $895 | $344K | Form 4 ↗ | ||
| MPWR | Sell F | October 30, 2025 | October 31, 2025 | 1d | 54,543 | $1,097 | $59.8M | Form 4 ↗ | ||
| MPWR | Other A | October 25, 2025 | October 28, 2025 | 3d | 135,520 | — | — | Form 4 ↗ | ||
| MPWR | Sell S | October 24, 2025 | October 24, 2025 | 0d | 1,300 | $1,088 | $1.4M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | October 16, 2025 | October 17, 2025 | 1d | 1,313 | $1,031 | $1.4M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | October 16, 2025 | October 17, 2025 | 1d | 1,499 | $1,021 | $1.5M | 10b5-1 plan | Form 4 ↗ | |
| MPWR | Sell S | October 15, 2025 | October 17, 2025 | 2d | 14,028 | $1,016 | $14.3M | 10b5-1 plan | Form 4 ↗ |
Filings
| Filed | Form | Accession | Rows | Status | Source |
|---|---|---|---|---|---|
| September 2, 2026 | Form 4 | 0001214659-26-011363 | 2 | published | EDGAR ↗ |
| May 29, 2026 | Form 4 | 0001214659-26-006933 | 1 | published | EDGAR ↗ |
| May 27, 2026 | Form 4 | 0001214659-26-006798 | 2 | published | EDGAR ↗ |
| April 10, 2026 | Form 4 | 0001214659-26-004535 | 10 | published | EDGAR ↗ |
| April 8, 2026 | Form 4 | 0001214659-26-004460 | 8 | published | EDGAR ↗ |
| April 3, 2026 | Form 4 | 0001214659-26-004341 | 5 | published | EDGAR ↗ |
| April 1, 2026 | Form 4 | 0001214659-26-004185 | 8 | published | EDGAR ↗ |
| February 10, 2026 | Form 4 | 0001214659-26-001450 | 1 | published | EDGAR ↗ |
| February 5, 2026 | Form 4 | 0001214659-26-001254 | 1 | published | EDGAR ↗ |
| December 30, 2025 | Form 4 | 0001214659-25-018632 | 2 | published | EDGAR ↗ |
| November 28, 2025 | Form 4 | 0001214659-25-017303 | 19 | published | EDGAR ↗ |
| November 28, 2025 | Form 4 | 0001214659-25-017305 | 9 | published | EDGAR ↗ |
| October 31, 2025 | Form 4 | 0001214659-25-015708 | 1 | published | EDGAR ↗ |
| October 28, 2025 | Form 4 | 0001214659-25-015478 | 1 | published | EDGAR ↗ |
| October 24, 2025 | Form 4 | 0001214659-25-015290 | 1 | published | EDGAR ↗ |
| October 17, 2025 | Form 4 | 0001214659-25-015041 | 3 | published | EDGAR ↗ |
Other insiders at MONOLITHIC POWER SYSTEMS INC
- Hsing Michael CEO 93 rows
- BLEGEN THEODORE EVP and CFO 81 rows
- Sciammas Maurice EVP, WW Sales & Marketing 71 rows
- Elmiger Eugen J Director 10 rows
- Lee Victor K Director 9 rows
- DEAN ROBERT W II Interim CFO 8 rows
- Xiao Deming EVP, Global Operations 8 rows
- CHANG KUO WEI HERBERT Director 5 rows
- Zhou Jeff Director 5 rows
- Wynne Eileen Director 2 rows
Everyone on file, with contracts and lobbying under the company's name: MONOLITHIC POWER SYSTEMS INC.
Guides for this page
- What is SEC Form 4? Who files: officers, directors and owners of more than 10% of a class of the company's shares.
- Form 4 transaction codes P = purchase. S = sale. These are the two market trades.
- Insider buying vs insider selling Selling outweighs buying by a wide margin in normal times.
- Rule 10b5-1 trading plans The plan must be set up when the insider has no important non-public information.
- What disclosure data cannot tell you Filings are late by design: up to 45 days for Congress, two business days for insiders.
Sources and method
| Source | Filings | Rows | First filed | Newest filed | Read the originals |
|---|---|---|---|---|---|
| SEC EDGAR, Form 4 | 16 | 74 | October 17, 2025 | September 2, 2026 | Form 4 list on EDGAR |
Site built October 22, 2026. Every row in the tables above links to its own filing. To quote a figure, use the Cite button at the top of the page; see how to cite and reuse.
Every row comes from the reporting owner's Form 4 as filed with the SEC (EDGAR ownership XML), read daily. "Value" is shares × the reported price; code P is an open-market purchase, S a sale, M an option exercise, A a grant. The lag is the filing date minus the trade date; Form 4 is due within two business days. Amendments (4/A) are not merged. Details on the methodology page; report an error on corrections.
Not investment advice. Figures are public disclosures shown as filed; they may lag the trade and may be amended later. No recommendation is made or implied.