Monolithic Power Systems Inc (MPWR)
Who owns Monolithic Power Systems Inc (MPWR)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 96.3% of the shares are freely tradable; institutional investors hold 101.1%.
Ownership Structure
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 12.36 | 6,072,467 | +1.8 | 03/31/2026 |
| Vanguard Group Inc | 12.28 | 6,034,394 | -0.7 | 12/31/2025 |
| FMR Inc | 8.96 | 4,400,831 | +10.7 | 03/31/2026 |
| Vanguard Capital Management, LLC | 6.28 | 3,083,449 | +0.0 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 5.12 | 2,516,492 | +0.0 | 03/31/2026 |
| State Street Corp | 4.45 | 2,188,454 | +0.4 | 03/31/2026 |
| CI Private Wealth LLC | 4.27 | 2,098,506 | +3,815.3 | 12/31/2025 |
| Amvescap Plc. | 3.02 | 1,485,093 | +3.5 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Fidelity Select Semiconductors | 3.40 | 1,668,570 | +1.5 | 04/30/2026 |
| Vanguard Total Stock Mkt Idx Inv | 3.00 | 1,474,124 | +0.3 | 04/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 25. Jul 2026 | Dean Robert W Ii | Interim CFO | Other | 1,359 | 0.00 | – |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 110 | 1,405.71 | 154,628 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 117 | 1,400.45 | 163,853 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 213 | 1,396.16 | 297,382 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 410 | 1,384.11 | 567,485 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 418 | 1,378.73 | 576,309 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 472 | 1,375.47 | 649,222 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 240 | 1,369.18 | 328,603 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 50 | 1,388.19 | 69,410 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 5,640 | 1,352.95 | 7,630,638 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 1,506 | 1,348.91 | 2,031,458 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 1,864 | 1,344.16 | 2,505,514 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 1,460 | 1,339.59 | 1,955,801 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 776 | 1,334.59 | 1,035,642 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 464 | 1,329.30 | 616,795 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 409 | 1,323.93 | 541,487 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 274 | 1,318.42 | 361,247 |
| 15. Jul 2026 | Sciammas Maurice | EVP, WW Sales & Marketing | Sell | 527 | 1,314.03 | 692,494 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character.
View all insider transactions →Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.