Quick Takeaways
- MPWR - MONOLITHIC POWER SYSTEMS INC has 13 insiders with reported activity on this page.
- Net insider value flow over the last year: -$600,350,189.
- Recent transaction rows are available for direct filing-level review.
- Info
- Insider Trading
- Financials
- Holders
Insider Transactions Reported by 13 Insiders of MONOLITHIC POWER SYSTEMS INC
- Symbol
- MPWR on Nasdaq
- Location
- West Palm Beach, FL
What Changed
- Buy value: ; sell value: $600,350,188.
- Net share flow: -585,905.
Why This Matters
- This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
- Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.
Official SEC Source
Insider trading overview
Last 12 monthsNet insider flow leans to selling over the last 12 months. Net value: -$600,350,189.
Buys
$0
Shares: 0
Insiders: 0
Sells
$600,350,189
Shares: 585,905
Insiders: 10
Net
-$600,350,189
Shares: -585,905
Insiders: -10
| Window (months) | Buy shares | Sell shares | Buy $ | Sell $ | Net $ |
|---|---|---|---|---|---|
| 0-3 | 0 | 292,606 | $0 | $339,204,490 | -$339,204,490 |
| 3-6 | 0 | 185,116 | $0 | $174,067,128 | -$174,067,128 |
| 6-9 | 0 | 89,933 | $0 | $73,994,870 | -$73,994,870 |
| 9-12 | 0 | 18,250 | $0 | $13,083,700 | -$13,083,700 |
MONOLITHIC POWER SYSTEMS INC executives and other stock owners filed with the SEC include:
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Mr. Michael R. Hsing | CEO, Director | $1,220,392,816 | -$271,899,379 | -18% | Mixed | 12 Feb 2026 |
| Mr. Deming Xiao | EVP, Global Operations | $299,991,142 | -$57,989,590 | -16% | Mixed | 06 Feb 2026 |
| Mr. Maurice Sciammas | EVP, WW Sales & Marketing | $248,978,157 | -$70,038,952 | -22% | Mixed | 01 Apr 2026 |
| Saria Tseng | EVP & General Counsel | $208,615,464 | -$143,372,845 | -41% | Mixed | 08 Apr 2026 |
| Theodore Blegen | EVP and CFO | $106,631,372 | -$49,384,778 | -32% | Mixed | 06 Feb 2026 |
| Mr. Victor K. Lee | Director | $33,644,712 | -$1,995,099 | -5.6% | Filing P/S | 09 Feb 2026 |
| Mr. Eugen J. Elmiger | Director | $15,772,478 | -$3,386,841 | -18% | Mixed | 03 Feb 2026 |
| Mr. James C. Moyer | Director | $15,372,900 | Mixed | 29 Aug 2024 | ||
| Mr. Robert W. Dean II | Interim CFO | $9,723,430 | Mixed | 27 Feb 2026 | ||
| Mr. Jeff Zhou | Director | $5,256,888 | -$673,910 | -11% | Mixed | 03 Feb 2026 |
| Ms. Eileen Wynne | Director | $1,216,335 | Mixed | 03 Feb 2026 | ||
| Ms. Carintia Martinez | Director | $967,086 | -$1,260,000 | -57% | Mixed | 03 Feb 2026 |
| Mr. Herbert Chang | Director | $557,411 | -$348,794 | -38% | Mixed | 03 Feb 2026 |
Top shareholders of MONOLITHIC POWER SYSTEMS INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| VANGUARD GROUP INC |
13F
|
Company |
13%
|
6,034,394
|
$5,469,333,346 | — | 31 Dec 2025 | |
| BlackRock, Inc. |
13F
13D/G
|
Company |
10%
from 13D/G
|
5,962,391
|
$5,404,072,656 | — | 31 Dec 2025 | |
| FMR LLC |
13D/G
13F
|
Company |
8.3%
|
3,977,008
|
$3,604,601,251 | $0 | 31 Dec 2025 | |
| STATE STREET CORP |
13F
|
Company |
4.6%
|
2,180,419
|
$1,979,609,520 | — | 31 Dec 2025 | |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13F
|
Company |
3.5%
|
1,691,394
|
$1,533,013,000 | — | 31 Dec 2025 | |
| Invesco Ltd. |
13F
|
Company |
3%
|
1,434,689
|
$1,300,344,794 | — | 31 Dec 2025 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
2.9%
|
1,382,280
|
$1,248,435,634 | — | 31 Dec 2025 | |
| Mr. Michael R. Hsing |
3/4/5
|
CEO, Director |
2.2%
|
1,034,099
|
$1,220,392,816 | -$271,899,379 | 12 Feb 2026 | |
| FRANKLIN RESOURCES INC |
13F
|
Company |
2.2%
|
1,049,409
|
$951,142,476 | — | 31 Dec 2025 | |
| NORGES BANK |
13F
|
Company |
1.5%
|
726,705
|
$658,656,344 | — | 31 Dec 2025 | |
| T. Rowe Price Investment Management, Inc. |
13F
|
Company |
1.5%
|
724,494
|
$656,653,000 | — | 31 Dec 2025 | |
| FIRST TRUST ADVISORS LP |
13F
|
Company |
1.5%
|
701,454
|
$635,770,374 | — | 31 Dec 2025 | |
| MORGAN STANLEY |
13F
|
Company |
1.4%
|
649,070
|
$588,293,698 | — | 31 Dec 2025 | |
| BARCLAYS PLC |
13F
|
Company |
1.3%
|
604,802
|
$548,168,340 | — | 31 Dec 2025 | |
| GOLDMAN SACHS GROUP INC |
13F
|
Company |
1.2%
|
593,742
|
$538,143,966 | — | 31 Dec 2025 | |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ |
13F
|
Company |
1.2%
|
570,719
|
$517,276,874 | — | 31 Dec 2025 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
1.1%
|
549,575
|
$498,112,749 | — | 31 Dec 2025 | |
| JPMORGAN CHASE & CO |
13F
|
Company |
1.1%
|
512,273
|
$464,305,775 | — | 31 Dec 2025 | |
| VAN ECK ASSOCIATES CORP |
13F
|
Company |
1%
|
502,312
|
$455,276,000 | — | 31 Dec 2025 | |
| BROWN ADVISORY INC |
13F
|
Company |
1%
|
500,755
|
$453,887,111 | — | 31 Dec 2025 | |
| NORTHERN TRUST CORP |
13F
|
Company |
1%
|
483,700
|
$438,406,331 | — | 31 Dec 2025 | |
| UBS Group AG |
13F
|
Company |
0.92%
|
438,985
|
$397,878,444 | — | 31 Dec 2025 | |
| Rafferty Asset Management, LLC |
13F
|
Company |
0.83%
|
396,464
|
$359,339,111 | — | 31 Dec 2025 | |
| WELLINGTON MANAGEMENT GROUP LLP |
13F
|
Company |
0.8%
|
384,770
|
$348,740,137 | — | 31 Dec 2025 | |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC |
13F
|
Company |
0.76%
|
365,384
|
$331,169,442 | — | 31 Dec 2025 | |
| Legal & General Group Plc |
13F
|
Company |
0.74%
|
356,639
|
$323,243,329 | — | 31 Dec 2025 | |
| VOYA INVESTMENT MANAGEMENT LLC |
13F
|
Company |
0.71%
|
339,732
|
$307,919,496 | — | 31 Dec 2025 | |
| Mr. Deming Xiao |
3/4/5
|
EVP, Global Operations |
0.54%
|
260,723
|
$299,991,142 | -$57,989,590 | 06 Feb 2026 | |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC |
13F
|
Company |
0.67%
|
318,797
|
$288,944,848 | — | 31 Dec 2025 | |
| FIL Ltd |
13F
|
Company |
0.66%
|
316,089
|
$286,490,425 | — | 31 Dec 2025 | |
| Bank of New York Mellon Corp |
13F
|
Company |
0.62%
|
295,119
|
$267,484,331 | — | 31 Dec 2025 | |
| KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC |
13F
|
Company |
0.61%
|
294,043
|
$266,509,700 | — | 31 Dec 2025 | |
| Mr. Maurice Sciammas |
3/4/5
|
EVP, WW Sales & Marketing |
0.57%
|
274,414
|
$248,978,157 | -$70,038,952 | 01 Apr 2026 | |
| SG Americas Securities, LLC |
13F
|
Company |
0.55%
|
262,231
|
$237,676,000 | — | 31 Dec 2025 | |
| VAUGHAN NELSON INVESTMENT MANAGEMENT, L.P. |
13F
|
Company |
0.54%
|
257,644
|
$233,518,217 | — | 31 Dec 2025 | |
| BNP PARIBAS FINANCIAL MARKETS |
13F
|
Company |
0.52%
|
247,127
|
$223,986,028 | — | 31 Dec 2025 | |
| CITIGROUP INC |
13F
|
Company |
0.51%
|
245,479
|
$222,492,056 | — | 31 Dec 2025 | |
| Saria Tseng |
3/4/5
|
EVP & General Counsel |
0.33%
|
157,983
|
$208,615,464 | -$143,372,845 | 08 Apr 2026 | |
| RAYMOND JAMES FINANCIAL INC |
13F
|
Company |
0.44%
|
211,484
|
$193,722,897 | — | 31 Dec 2025 | |
| AMERICAN CENTURY COMPANIES INC |
13F
|
Company |
0.42%
|
203,564
|
$184,507,922 | — | 31 Dec 2025 | |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND |
13F
|
Company |
0.42%
|
202,864
|
$183,867,815 | — | 31 Dec 2025 | |
| HSBC HOLDINGS PLC |
13F
|
Company |
0.42%
|
200,626
|
$182,310,004 | — | 31 Dec 2025 | |
| Neuberger Berman Group LLC |
13F
|
Company |
0.38%
|
181,706
|
$164,690,961 | — | 31 Dec 2025 | |
| ROYAL BANK OF CANADA |
13F
|
Company |
0.37%
|
176,580
|
$160,045,000 | — | 31 Dec 2025 | |
| DEUTSCHE BANK AG\ |
13F
|
Company |
0.36%
|
174,325
|
$158,001,207 | — | 31 Dec 2025 | |
| PRINCIPAL FINANCIAL GROUP INC |
13F
|
Company |
0.35%
|
167,265
|
$151,604,133 | — | 31 Dec 2025 | |
| SEI INVESTMENTS CO |
13F
|
Company |
0.35%
|
166,693
|
$151,085,444 | — | 31 Dec 2025 | |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. |
13F
|
Company |
0.34%
|
165,234
|
$149,761,217 | — | 31 Dec 2025 | |
| Nuveen, LLC |
13F
|
Company |
0.34%
|
161,249
|
$146,149,644 | — | 31 Dec 2025 | |
| Allspring Global Investments Holdings, LLC |
13F
|
Company |
0.32%
|
153,328
|
$143,562,562 | — | 31 Dec 2025 |
Recent Insider Transactions by Companies or Individuals for MONOLITHIC POWER SYSTEMS INC
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Value $ | * Price $ | Shares | Shares Owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Saria Tseng | MPWR | Common Stock | Sale | -5.4% | $11,698,654 | $1305.22 | -8,963 | 156,983 | 08 Apr 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -4.4% | $8,918,434 | $1167.95 | -7,636 | 165,946 | 06 Apr 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -0.8% | $1,586,924 | $1133.52 | -1,400 | 173,582 | 01 Apr 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.36% | $33,493 | $1116.44 | -30 | 1,239 | 01 Apr 2026 | Clement Sciammas Trust |
| Saria Tseng | MPWR | Common Stock | Sale | -12.8% | $25,943,638 | $1010.50 | -25,674 | 174,982 | 30 Mar 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.31% | $32,852 | $1095.07 | -30 | 1,269 | 20 Mar 2026 | Clement Sciammas Trust |
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -3.58% | $38,670,257 | $1171.83 | -33,000 | 888,234 | 12 Feb 2026 | Direct |
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -3.46% | $39,234,212 | $1188.92 | -33,000 | 921,234 | 11 Feb 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -13.3% | $235,995 | $1179.98 | -200 | 1,299 | 11 Feb 2026 | Clement Sciammas Trust |
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -3.44% | $38,837,435 | $1142.28 | -34,000 | 954,234 | 10 Feb 2026 | Direct |
| Mr. Victor K. Lee | MPWR | Common Stock | Sale | -1.42% | $484,864 | $1212.16 | -400 | 27,756 | 09 Feb 2026 | Direct |
| Mr. Deming Xiao | MPWR | Common Stock | Sale | -8.84% | $26,790,370 | $1171.16 | -22,875 | 235,932 | 06 Feb 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -10.2% | $26,790,370 | $1171.16 | -22,875 | 200,626 | 06 Feb 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -11.4% | $26,790,370 | $1171.16 | -22,875 | 178,625 | 06 Feb 2026 | Direct |
| Theodore Blegen | MPWR | Common Stock | Sale | -20.9% | $25,443,531 | $1171.16 | -21,725 | 82,353 | 06 Feb 2026 | Direct |
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -5.27% | $64,323,824 | $1171.16 | -54,923 | 988,234 | 06 Feb 2026 | Direct |
| Ms. Eileen Wynne | MPWR | Common Stock | Award | 16.4% | 189 | 1,342 | 03 Feb 2026 | Direct | ||
| Mr. Jeff Zhou | MPWR | Common Stock | Award | 3.37% | 189 | 5,800 | 03 Feb 2026 | Direct | ||
| Mr. Eugen J. Elmiger | MPWR | Common Stock | Award | 1.1% | 189 | 17,402 | 03 Feb 2026 | Direct | ||
| Mr. Victor K. Lee | MPWR | Common Stock | Award | 0.68% | 189 | 28,156 | 03 Feb 2026 | Direct | ||
| Ms. Carintia Martinez | MPWR | Common Stock | Award | 21.5% | 189 | 1,067 | 03 Feb 2026 | Direct | ||
| Mr. Deming Xiao | MPWR | Common Stock | Award | 28.4% | 57,170 | 258,807 | 03 Feb 2026 | Direct | ||
| Theodore Blegen | MPWR | Common Stock | Award | 59.3% | 38,745 | 104,078 | 03 Feb 2026 | Direct | ||
| Saria Tseng | MPWR | Common Stock | Award | 34.4% | 57,170 | 223,501 | 03 Feb 2026 | Direct | ||
| Mr. Michael R. Hsing | MPWR | Common Stock | Award | 15.1% | 136,825 | 1,043,157 | 03 Feb 2026 | Direct | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Award | 39.6% | 57,170 | 201,500 | 03 Feb 2026 | Direct | ||
| Mr. Herbert Chang | MPWR | Common Stock | Award | 44.4% | 189 | 615 | 03 Feb 2026 | Direct | ||
| Theodore Blegen | MPWR | Common Stock | Sale | -4.39% | $3,389,266 | $1129.76 | -3,000 | 65,333 | 02 Feb 2026 | Direct |
| Mr. Victor K. Lee | MPWR | Common Stock | Sale | -2.1% | $558,516 | $930.86 | -600 | 27,967 | 02 Jan 2026 | Direct |
| Theodore Blegen | MPWR | Common Stock | Sale | -4.21% | $2,821,399 | $940.47 | -3,000 | 68,332 | 02 Jan 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Gift | 1,000 | 1,000 | 24 Dec 2025 | C&T Discovery Foundation | |||
| Saria Tseng | MPWR | Common Stock | Gift | -0.6% | -1,000 | 166,331 | 24 Dec 2025 | Direct | ||
| Mr. Victor K. Lee | MPWR | Common Stock | Sale | -3.38% | $951,719 | $951.72 | -1,000 | 28,567 | 24 Dec 2025 | Direct |
| Mr. Michael R. Hsing | MPWR | Common Stock | Gift | -1.34% | -12,337 | 906,332 | 09 Dec 2025 | Direct | ||
| Theodore Blegen | MPWR | Common Stock | Sale | -4.04% | $2,724,623 | $908.21 | -3,000 | 71,332 | 01 Dec 2025 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -10.7% | $18,529,316 | $926.47 | -20,000 | 167,331 | 26 Nov 2025 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -9.65% | $18,083,638 | $904.18 | -20,000 | 187,331 | 25 Nov 2025 | Direct |
| Mr. Herbert Chang | MPWR | Common Stock | Sale | -19% | $89,697 | $896.97 | -100 | 426 | 25 Nov 2025 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.68% | $3,559,434 | $895.23 | -3,976 | 144,330 | 24 Nov 2025 | Direct |
| Mr. Herbert Chang | MPWR | Common Stock | Sale | -16% | $87,397 | $873.97 | -100 | 526 | 21 Nov 2025 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -15.9% | $24,656,387 | $881.66 | -27,966 | 148,306 | 19 Nov 2025 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -3.84% | $6,121,059 | $870.21 | -7,034 | 176,272 | 19 Nov 2025 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | 10.1% | 4,530 | 49,460 | 13 Nov 2025 | Sciammas Family Trust | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | -14.5% | -4,530 | 26,660 | 13 Nov 2025 | Various Sciammas GRATs | ||
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -3.87% | $35,724,380 | $965.52 | -37,000 | 918,669 | 12 Nov 2025 | Direct |
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -4.02% | $38,335,721 | $958.39 | -40,000 | 955,669 | 11 Nov 2025 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -13.3% | $197,362 | $986.81 | -200 | 1,299 | 05 Nov 2025 | Rosalind Sciammas Brokerage Account |
| Theodore Blegen | MPWR | Common Stock | Sale | -3.88% | $3,073,278 | $1024.43 | -3,000 | 74,332 | 03 Nov 2025 | Direct |
| Mr. Michael R. Hsing | MPWR | Common Stock | Tax liability | -10.9% | -121,918 | 995,669 | 30 Oct 2025 | Direct | ||
| Theodore Blegen | MPWR | Common Stock | Tax liability | -38.4% | -48,298 | 77,332 | 30 Oct 2025 | Direct |
* An asterisk sign (*) next to the price indicates that the price is likely invalid.