MPWR · Monolithic Power Systems, Inc.
Trades by corporate insiders — officers, directors and holders of more than 10% of the shares — disclosed to the SEC on Forms 4 and 5. Form 3 supplies initial ownership rather than a trade; Form 4 must be filed within two business days of the trade.
Insider Sentiment Score
Peer-relative 0–100 rank of how aggressively insiders accumulated over the trailing 90 days. See the full ranking.
| Date | Insider | Role | Type | Security | Shares |
|---|---|---|---|---|---|
| 2026-08-24 | DEAN ROBERT W II |
Interim CFO |
Sell↓
Filing footnotes — Common Stock (Direct)
The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,296.07 to $1,298.01. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
32 |
| 2026-08-24 | CHANG KUO WEI HERBERT |
Director |
Sell↓
|
Common Stock
|
50 |
| 2026-08-24 | DEAN ROBERT W II |
Interim CFO |
Other↓
Filing footnotes — Common Stock (Direct)
The reported transaction involved a transfer of securities from the reporting person's direct holdings to an individual who is not an immediate family member sharing the same household. No funds were exchanged and no sale of shares occurred in the transfer. Following the completion of the transfer, the reporting person no longer retains any pecuniary interest in the shares. |
Common Stock
|
5 |
| 2026-08-17 | DEAN ROBERT W II |
Interim CFO |
Sell↓
Filing footnotes — Common Stock (Direct)
The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units. |
Common Stock
|
6 |
| 2026-08-11 | CHANG KUO WEI HERBERT |
Director |
Sell↓
|
Common Stock
|
50 |
| 2026-08-05 | DEAN ROBERT W II |
Interim CFO |
Sell↓
|
Common Stock
|
105 |
| 2026-08-04 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Gift↑
Filing footnotes — Common Stock (Indirect)
25,000 shares were received by two GRATs, of which the reporting person is a trustee, from the reporting person's direct holdings. No funds were exchanged and no sale of shares occurred in the transfer. |
Common Stock
(I)
|
25,000 |
| 2026-08-04 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Gift↓
Filing footnotes — Common Stock (Direct)
25,000 shares were transferred from the reporting person's direct holdings to two GRATs, of which the reporting person is a trustee. No funds were exchanged and no sale of shares occurred in the transfer. |
Common Stock
|
25,000 |
| 2026-08-03 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Indirect)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/19/2025. |
Common Stock
(I)
|
30 |
| 2026-07-25 | DEAN ROBERT W II |
Interim CFO |
Award↑
Filing footnotes — Common Stock (Direct)
On July 25, 2023, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of stock price targets and relative total stockholder return percentile rank over a three-year performance period. On July 25, 2026, the Company's Compensation Committee of the Board of Directors certified and approved the achievement of the performance conditions for the MSUs, which resulted in an award of 1,359 shares to the reporting person. 1/3 of the shares will vest on July 25, 2027, 1/3 of the shares will vest on July 25, 2028, and 1/3 of the shares will vest on July 25, 2029, pursuant to the grant agreement. |
Common Stock
|
1,359 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,366.15 to $1,371.04. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
240 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,311.45 to $1,316.40 The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
527 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,341.99 to $1,346.96. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
1,864 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,404.25 to $1,406.04. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
110 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,316.56 to $1,321.56. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
274 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,371.23 to $1,376.20. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
472 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,321.72 to $1,326.11. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
409 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,326.94 to $1,331.90. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
464 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,352.13 to $1,357.03. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
5,640 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,388.18 to $1,388.22. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
50 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,381.79 to $1,386.22. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
410 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,398.97 to $1,400.85. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
117 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,336.97 to $1,341.96. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
1,460 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,393.94 to $1,398.92. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
213 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,376.51 to $1,381.11. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
418 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,331.95 to $1,336.95. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
776 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,347.09 to $1,352.00. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
1,506 |
| 2026-07-15 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Direct)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/24/2025. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,357.88 to $1,362.57. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
50 |
| 2026-07-01 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Indirect)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/19/2025. |
Common Stock
(I)
|
30 |
| 2026-06-01 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Sell↓
Filing footnotes — Common Stock (Indirect)
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on 11/19/2025. |
Common Stock
(I)
|
30 |
| 2026-05-29 | Sciammas Maurice |
EVP, WW Sales & Marketing |
Gift↓
Filing footnotes — Common Stock (Indirect)
The reported transaction involved distributions of securities from the various GRATs, of which the reporting person is a trustee, to individuals who are not immediate family members sharing the same household. No funds were exchanged and no sale of shares occurred in the distributions. Following the completion of the distributions, neither the GRATs nor the reporting person retains any pecuniary interest in the shares. |
Common Stock
(I)
|
12,472 |
| 2026-05-27 | Tseng Saria |
Director |
Sell↓
|
Common Stock
|
7,565 |
| 2026-05-26 | Zhou Jeff |
Director |
Sell↓
|
Common Stock
|
486 |
| 2026-05-26 | DEAN ROBERT W II |
Interim CFO |
Sell↓
Filing footnotes — Common Stock (Direct)
The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units. The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,647.84 to $1,650.16. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
22 |
| 2026-05-22 | Tseng Saria |
Director |
Gift↓
Filing footnotes — Common Stock (Direct)
The reported transaction involved a transfer of securities from the reporting person's direct holdings to an individual who is not an immediate family member sharing the same household. No funds were exchanged and no sale of shares occurred in the transfer. Following the completion of the transfer, the reporting person no longer retains any pecuniary interest in the shares. |
Common Stock
|
200 |
| 2026-05-22 | Tseng Saria |
Director |
Sell↓
|
Common Stock
|
5,000 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,516.26 to $1,519.25. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
352 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,474.95 to $1,479.85. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
4,082 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,459.96 to $1,464.86. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Ending balance includes 29 shares acquired on February 17, 2026 through the Company's qualified ESPP program. |
Common Stock
|
3,424 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $,1495.74 to $1,500.72. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
608 |
| 2026-05-18 | DEAN ROBERT W II |
Interim CFO |
Sell↓
Filing footnotes — Common Stock (Direct)
The reported sale was to cover tax withholding obligations upon the vesting of restricted stock units. |
Common Stock
|
4 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,490.17 to $1,494.10. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
862 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,484.95 to $1,489.73. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
6,688 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,521.33 to $1,521.56. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
130 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,479.99 to $1,484.93. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
5,737 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,464.97 to $1,469.94. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
5,819 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,510.68 to $1,515.44. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
551 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,469.95 to $1,474.94. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
5,049 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,500.75 to $1,505.70. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
2,929 |
| 2026-05-18 | Hsing Michael |
Director, CEO |
Sell↓
Filing footnotes — Common Stock (Direct)
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,505.70 to $1,510.67. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. |
Common Stock
|
3,769 |