Comparable stake leader
BlackRock, Inc.
SEC ownership of MONOLITHIC POWER SYSTEMS, INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001280452.
Disclosed value leader
BlackRock, Inc.
Comparable rows
5/50
Latest evidence
03 Nov 2026
- Public ticker
- MPWR on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
5 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
03 Nov 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001280452
- Issuer location
- West Palm Beach, FL
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of MONOLITHIC POWER SYSTEMS, INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
5/50
Latest evidence
03 Nov 2026
13F
13D/G
3/4/5
Lead comparable stake: 10%
45 rows are not safely comparable across share classes.
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 10%.
5 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
10%
FMR LLC
9.1%
VANGUARD CAPITAL MANAGEMENT LLC
7.2%
Invesco Ltd.
5.2%
VANGUARD PORTFOLIO MANAGEMENT LLC
5.1%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
Company
|
10%
Reported 13D/G
· 31 Dec 2025
|
$7,727,288,729
5,589,925 shares
|
— | 30 Jun 2026 |
| FMR LLC |
13F
13D/G
Company
|
9.1%
Reported 13D/G
· 30 Sep 2026
|
$7,156,835,733
5,177,258 shares
|
— | 30 Jun 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
13D/G
Company · Vanguard Capital Management
|
7.2%
Reported 13D/G
· 31 Mar 2026
|
$4,322,302,424
3,126,756 shares
|
— | 30 Jun 2026 |
| Invesco Ltd. |
13D/G
13F
Company
|
5.2%
Reported 13D/G
· 31 Dec 2025
|
$3,471,078,313
2,510,980 shares
|
$0 | 31 Dec 2025 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
13D/G
Company · Vanguard Portfolio Management
|
5.1%
Reported 13D/G
· 31 Mar 2026
|
$3,462,615,505
2,504,858 shares
|
— | 30 Jun 2026 |
| STATE STREET CORP |
13F
Company
|
—
denominator unverified
|
$3,159,218,647
2,282,186 shares
|
— | 30 Jun 2026 |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
Company
|
—
denominator unverified
|
$1,646,916,316
1,195,281 shares
|
— | 30 Jun 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13F
Company
|
—
denominator unverified
|
$1,350,287,000
976,798 shares
|
— | 30 Jun 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$724,464,606.
Buys
$0
Insiders: 0
Sells
$724,464,606
Insiders: 11
Net
-$724,464,606
Shares: -611,051
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 611,051
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 30,138 | $0 | $40,534,134 | -$40,534,134 |
| 3-6 | 0 | 80,272 | $0 | $120,212,662 | -$120,212,662 |
| 6-9 | 0 | 188,592 | $0 | $237,946,792 | -$237,946,792 |
| 9-12 | 0 | 312,049 | $0 | $325,771,018 | -$325,771,018 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-14 of 14 reporting-owner rows connected to MONOLITHIC POWER SYSTEMS, INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
14
Largest Forms 3/4/5 holder
Mr. Michael R. Hsing
Net 12M change
-$724.46M
Full value: -$724,464,608 · USD · 12-month changeLatest report
03 Nov 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Mr. Michael R. Hsing | CEO, Director | $1,311,973,093 | -$354,785,045 | -21% | Mixed | 28 Sep 2026 |
| Mr. Deming Xiao | EVP, Global Operations | $369,281,405 | -$76,426,930 | -17% | Mixed | 06 May 2026 |
| Mr. Maurice Sciammas | EVP, WW Sales & Marketing | $315,855,746 | -$101,188,772 | -24% | Median | 03 Nov 2026 |
| Saria Tseng | EVP & General Counsel | $200,743,554 | -$132,343,624 | -40% | Mixed | 31 Aug 2026 |
| Theodore Blegen | EVP and CFO | $106,631,372 | -$34,378,821 | -24% | Mixed | 06 Feb 2026 |
| Mr. Victor K. Lee | Director | $33,644,712 | -$1,995,099 | -5.6% | Filing P/S | 09 Feb 2026 |
| Mr. James C. Moyer | Director | $15,372,900 | Mixed | 29 Aug 2024 | ||
| Mr. Robert W. Dean II | Interim CFO | $9,889,403 | -$233,701 | -2.3% | Mixed | 24 Aug 2026 |
| Mr. Eugen J. Elmiger | Director | $8,643,956 | -$19,019,482 | -69% | Filing P/S | 06 May 2026 |
| Mr. Jeff Zhou | Director | $6,384,000 | -$3,250,763 | -34% | Filing P/S | 26 May 2026 |
| Mr. Frank Anthony Balow III | Chief Financial Officer | $3,962,174 | Median | 27 Oct 2026 | ||
| Ms. Eileen Wynne | Director | $1,593,758 | -$530,198 | -25% | Filing P/S | 06 May 2026 |
| Ms. Carintia Martinez | Director | $967,086 | Mixed | 03 Feb 2026 | ||
| Mr. Herbert Chang | Director | $660,008 | -$312,173 | -32% | Filing P/S | 24 Aug 2026 |
Recent insider transactions for MONOLITHIC POWER SYSTEMS, INC.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | 36% | 13,000 | 49,062 | 03 Nov 2026 | Various Sciammas GRATs | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | -10.3% | -13,000 | 113,652 | 03 Nov 2026 | Direct | ||
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -3.54% | -$40,349,047 | $1344.97 | -30,000 | 818,264 | 28 Sep 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Gift | 2,000 | 2,000 | 31 Aug 2026 | C&T Family Trust | |||
| Saria Tseng | MPWR | Common Stock | Gift | -1.39% | -2,000 | 142,218 | 31 Aug 2026 | Direct | ||
| Mr. Robert W. Dean II | MPWR | Common Stock | Other | -0.07% | -5 | 7,089 | 24 Aug 2026 | Direct | ||
| Mr. Robert W. Dean II | MPWR | Common Stock | Sale | -0.45% | -$41,527 | $1297.72 | -32 | 7,094 | 24 Aug 2026 | Direct |
| Mr. Herbert Chang | MPWR | Common Stock | Sale | -8.85% | -$64,078 | $1281.57 | -50 | 515 | 24 Aug 2026 | Direct |
| Mr. Robert W. Dean II | MPWR | Common Stock | Sale | -0.08% | -$8,482 | $1413.64 | -6 | 7,126 | 17 Aug 2026 | Direct |
| Mr. Herbert Chang | MPWR | Common Stock | Sale | -8.13% | -$71,000 | $1420.00 | -50 | 565 | 11 Aug 2026 | Direct |
| Mr. Robert W. Dean II | MPWR | Common Stock | Sale | -1.45% | -$141,148 | $1344.27 | -105 | 7,132 | 05 Aug 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | 226% | 25,000 | 36,062 | 04 Aug 2026 | Various Sciammas GRATs | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | -16.5% | -25,000 | 126,644 | 04 Aug 2026 | Direct | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.61% | -$40,318 | $1343.94 | -30 | 1,119 | 03 Aug 2026 | Clement Sciammas Trust |
| Mr. Robert W. Dean II | MPWR | Common Stock | Award | 23.1% | 1,359 | 7,237 | 25 Jul 2026 | Direct | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -9% | -$20,245,937 | $1349.73 | -15,000 | 151,644 | 15 Jul 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.54% | -$40,548 | $1351.61 | -30 | 1,149 | 01 Jul 2026 | Clement Sciammas Trust |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.48% | -$46,018 | $1533.95 | -30 | 1,179 | 01 Jun 2026 | Clement Sciammas Trust |
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | -49.7% | -12,472 | 12,625 | 29 May 2026 | Various Sciammas GRATs | ||
| Saria Tseng | MPWR | Common Stock | Sale | -4.98% | -$12,860,500 | $1700.00 | -7,565 | 144,218 | 27 May 2026 | Direct |
| Mr. Robert W. Dean II | MPWR | Common Stock | Sale | -0.37% | -$36,290 | $1649.56 | -22 | 5,878 | 26 May 2026 | Direct |
| Mr. Jeff Zhou | MPWR | Common Stock | Sale | -11.3% | -$816,480 | $1680.00 | -486 | 3,800 | 26 May 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Sale | -3.19% | -$7,932,150 | $1586.43 | -5,000 | 151,783 | 22 May 2026 | Direct |
| Saria Tseng | MPWR | Common Stock | Gift | -0.13% | -200 | 156,783 | 22 May 2026 | Direct | ||
| Mr. Michael R. Hsing | MPWR | Common Stock | Sale | -4.5% | -$59,310,169 | $1482.75 | -40,000 | 848,263 | 18 May 2026 | Direct |
| Mr. Robert W. Dean II | MPWR | Common Stock | Sale | -0.07% | -$6,253 | $1563.28 | -4 | 5,900 | 18 May 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -6.72% | -$18,736,850 | $1561.40 | -12,000 | 166,644 | 15 May 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | 3.16% | 1,563 | 51,023 | 13 May 2026 | Sciammas Family Trust | ||
| Mr. Maurice Sciammas | MPWR | Common Stock | Gift | -5.86% | -1,563 | 25,097 | 13 May 2026 | Various Sciammas GRATs | ||
| Mr. Robert W. Dean II | MPWR | Common Stock | Other | -26.8% | -2,156 | 5,904 | 13 May 2026 | Direct | ||
| Mr. Eugen J. Elmiger | MPWR | Common Stock | Sale | -69% | -$19,019,482 | $1584.96 | -12,000 | 5,402 | 06 May 2026 | Direct |
| Mr. Deming Xiao | MPWR | Common Stock | Sale | -12.7% | -$49,636,560 | $1654.55 | -30,000 | 205,959 | 06 May 2026 | Direct |
| Ms. Eileen Wynne | MPWR | Common Stock | Sale | -25% | -$530,198 | $1582.68 | -335 | 1,007 | 06 May 2026 | Direct |
| Mr. Jeff Zhou | MPWR | Common Stock | Sale | -10.4% | -$825,000 | $1650.00 | -500 | 4,286 | 06 May 2026 | Direct |
| Mr. Jeff Zhou | MPWR | Common Stock | Sale | -17.5% | -$1,609,283 | $1587.06 | -1,014 | 4,786 | 05 May 2026 | Direct |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -29.2% | -$601,848 | $1583.81 | -380 | 919 | 05 May 2026 | Rosalind Sciammas Brokerage Account |
| Mr. Maurice Sciammas | MPWR | Common Stock | Sale | -2.42% | -$47,662 | $1588.73 | -30 | 1,209 | 04 May 2026 | Clement Sciammas Trust |
| 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 |
* marks a reported price that did not pass the local price check.