Monolithic Power Systems, Inc. (MPWR) Shareholders & Insider Trades
Monolithic Power Systems shareholders at a glance
The largest holder of Monolithic Power Systems stock is Fidelity Management & Research Co. LLC, with 5.2 million shares (10.53% of the company), worth about $6.56 billion as of September 25, 2026. The 10 largest holders together own 49.0%.
In Q2 2026, 1,306 institutional holdings reports listed shares worth $65.70 billion.
Insiders reported 101 transactions in the last two years: 68 sales worth $678.89 million and no purchases. The newest one on file is from May 15, 2026 (Sciammas Maurice, Officer).
Major holders as of September 25, 2026; quarterly totals from institutional holdings reports (latest Q2 2026); insider transactions on file through May 15, 2026.
Monolithic Power Systems, Inc.
Shareholders Summary
2026Q2
Ownership by Type
Geographic Distribution
Largest Monolithic Power Systems shareholders
| Holder | Shares | % of company | Value |
|---|---|---|---|
| Fidelity Management & Research Co. LLC | 5.2 million | 10.53% | $6.6B |
| BlackRock Advisors LLC | 4.4 million | 8.97% | $5.6B |
| Vanguard Capital Management LLC | 3.1 million | 6.36% | $4.0B |
| Vanguard Portfolio Management LLC | 2.5 million | 5.10% | $3.2B |
| Invesco Advisers, Inc. | 2.3 million | 4.77% | $3.0B |
| State Street Corporation | 2.3 million | 4.64% | $2.9B |
| Geode Capital Management LLC | 1.2 million | 2.43% | $1.5B |
| BlackRock Life Ltd. | 1.1 million | 2.15% | $1.3B |
| Michael Hsing2.023 % | 994,128 | 2.02% | $1.3B |
| T. Rowe Price International Ltd. | 976,798 | 1.99% | $1.2B |
As of September 25, 2026.
Monolithic Power Systems institutional holdings by quarter
| Quarter | Reports | Shares | Value |
|---|---|---|---|
| Q2 2026 | 1,306 | – | $65.7B |
| Q1 2026 | 1,177 | 47.3 million | $51.6B |
| Q4 2025 | 1,118 | 51.6 million | $44.9B |
| Q3 2025 | 1,041 | – | $43.9B |
| Q2 2025 | 964 | 47.6 million | $34.8B |
| Q1 2025 | 915 | 46.9 million | $27.2B |
| Q4 2024 | 916 | 46.6 million | $27.6B |
| Q3 2024 | 924 | 47.5 million | $43.7B |
Shares and value held by institutions that file quarterly holdings reports (options not included).
Monolithic Power Systems insider trades
| Insider | Date | Title | Transaction | Value |
|---|---|---|---|---|
| Sciammas Maurice | May 15, 2026 | Officer | Sale at price 1550.36 - 1585.51 per share. | $18.7M |
| Sciammas Maurice | May 13, 2026 | Officer | Stock Gift at price 0.00 per share. | – |
| Elmiger Eugen J | May 6, 2026 | Director | Sale at price 1559.88 - 1600.14 per share. | $19.0M |
| Wynne Eileen | May 6, 2026 | Director | Sale at price 1582.68 per share. | $530,198 |
| Zhou Jeffrey | May 6, 2026 | Director | Sale at price 1574.48 - 1650.00 per share. | $2.4M |
| Xiao Deming | May 6, 2026 | Officer | Sale at price 1648.38 - 1661.38 per share. | $49.6M |
| Sciammas Maurice | May 5, 2026 | Officer | Sale at price 1583.81 per share. | $601,848 |
| Sciammas Maurice | May 4, 2026 | Officer | Sale at price 1588.73 per share. | $47,662 |
| Tseng Saria H | Apr 8, 2026 | General Counsel | Sale at price 1266.48 - 1321.94 per share. | $11.7M |
| Tseng Saria H | Apr 6, 2026 | General Counsel | Sale at price 1139.96 - 1179.50 per share. | $8.9M |
| Tseng Saria H | Apr 1, 2026 | General Counsel | Sale at price 1131.24 - 1136.99 per share. | $1.6M |
| Sciammas Maurice | Apr 1, 2026 | Officer | Sale at price 1116.44 per share. | $33,493 |
Newest 12 of 101 insider transactions in the last two years.
Questions and answers
Who owns the most Monolithic Power Systems stock?
Fidelity Management & Research Co. LLC, with 10.53% of the company (as of September 25, 2026). Next: BlackRock Advisors LLC (8.97%) and Vanguard Capital Management LLC (6.36%).
How many institutions own Monolithic Power Systems stock?
1,306 institutional holdings reports listed Monolithic Power Systems shares in Q2 2026 worth $65.70 billion.
Are Monolithic Power Systems insiders buying or selling the stock?
In the last two years insiders reported 68 sales and no purchases (101 transactions in all); the newest on file is from May 15, 2026.
