MONOLITHIC POWER SYSTEMS, INC. is an SEC registrant, filing under CIK 0001280452, classified as semiconductors and related devices. We track it alongside the rest of the Information Technology sector.
MPWR Form 4 activity by transaction type, last 90 days
Form 4 transaction type
Transactions
Shares
Total value
Open-market sale
14
30,273
$40.72M
Bona-fide gift
4
54,000
Other acquisition / disposition
1
5
Dollar totals cover purchases and sales only (codes P and S). Grants, option exercises, gifts and tax withholding are counted in shares, because none of them is a trade at a market price.
MPWR insider transactions (Form 4)
127
108 Form 4 filings on record, the earliest from Oct 2, 2024, newest first. Filing history page 3 of 3.
Footnote F1 (price): 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 $862.25 to $862.75. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F2 (price): 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 $866.16 to $866.51. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F3 (price): 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 $867.04 to $867.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F4 (price): 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 $868.00 to $868.94. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F5 (price): 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 $869.00 to $869.91. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F6 (price): 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 $870.07 to $870.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F7 (price): 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 $871.39 to $871.64. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F8 (price): 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 $872.74 to $872.89. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F9 (price): 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 $873.49 to $873.97. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F10 (price): 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 $874.09 to $874.90. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F1 (shares): 4,530 shares were transferred from two GRATs, on which the reporting person is a Trustee, to the Sciammas Family Trust, on which the reporting person is a Trustee. No funds were exchanged, and no sale of shares occurred in the transfer.
Footnote F2 (shares): 4,530 shares were received by the Sciammas Family Trust, on which the reporting person is a Trustee, and transferred from two GRATs, on which the reporting person is a Trustee. No funds were exchanged and no sale of shares occurred in the transfer.
Footnote F1 (price): 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 $952.05 to $952.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F2 (price): 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 $953.14 to $953.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F3 (price): 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 $954.00 to $954.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F4 (price): 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 $955.13 to $955.93. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F5 (price): 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 $956.00 to $956.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F6 (price): 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 $957.00 to $957.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F7 (price): 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 $958.13 to $958.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F8 (price): 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 $959.00 to $959.95. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F9 (price): 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 $960.00 to $960.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F10 (price): 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 $961.00 to $961.95. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F11 (price): 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 $962.00 to $962.97. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F12 (price): 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 $963.08 to $963.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F13 (price): 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 $964.00 to $964.77. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F14 (price): 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 $965.36 to $965.63. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F15 (price): 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 $966.06 to $966.80. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F16 (price): 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 $967.14 to $967.17. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F1 (shares): These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2025.
Footnote F2 (price): 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 $1,013.45 to $1,013.75. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F3 (price): 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 $1,014.12 to $1,014.64. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F4 (price): 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 $1,016.43 to $1,016.59. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F5 (price): 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 $1,019.10 to $1,019.68. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F6 (price): 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 $1,020.20 to $1,020.40. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F7 (price): 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 $1,021.04 to $1,021.32. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F8 (price): 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 $1,023.07 to $1,023.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F9 (price): 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 $1,024.02 to $1,024.99. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F10 (price): 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 $1,025.00 to $1,025.98. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F11 (price): 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 $1,027.03 to $1,027.89. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F12 (price): 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 $1,028.00 to $1,028.85. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F13 (price): 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 $1,029.14 to $1,029.77. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F14 (price): 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 $1,032.00 to $1,032.18. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F15 (price): 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 $1,038.40 to $1,038.42. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F1 (shares): The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a… Full note on SEC EDGAR
Footnote F1 (shares): The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a… Full note on SEC EDGAR
Footnote F1 (shares): The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a… Full note on SEC EDGAR
Footnote F1 (shares): The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a… Full note on SEC EDGAR
Footnote F1 (shares): The sales transaction reported in this Form 4 represents shares of common stock withheld by the Company to satisfy the income tax obligations in connection with the earnout and vesting of the market-based restricted stock units granted in October 2022, previously reported in a… Full note on SEC EDGAR
Footnote F1 (shares): On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025… Full note on SEC EDGAR
Footnote F1 (shares): On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025… Full note on SEC EDGAR
Footnote F1 (shares): On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025… Full note on SEC EDGAR
Footnote F1 (shares): On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025… Full note on SEC EDGAR
Footnote F1 (shares): On October 25, 2022, the reporting person was granted market-based restricted stock units ("MSUs") subject to the achievement of five stock price targets and relative total stockholder return percentile rank over a three-year performance and vesting period. On October 25, 2025… Full note on SEC EDGAR
Footnote F1 (shares): These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2025.
Footnote F2 (price): 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 $905.35 to $905.40. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F3 (price): 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 $907.30 to $907.37. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F4 (price): 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 $909.22 to $909.82. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F5 (price): 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 $911.04 to $911.66. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F6 (price): 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 $912.39 to $912.82. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F7 (price): 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 $913.84 to $913.87. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F8 (price): 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 $914.59 to $914.77. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F9 (price): 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 $915.01 to $915.68. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F10 (price): 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 $916.09 to $916.49. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
Footnote F11 (price): 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 $917.08 to $917.28. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange… Full note on SEC EDGAR
An insider files Form 144 before selling restricted or control stock. It announces a planned sale. If the sale goes ahead, it shows up later on a Form 4.
MONOLITHIC POWER SYSTEMS, INC. (MPWR) had 9 insider filings in the last 90 days, with the most recent on 30 September 2026. The full record for MPWR runs to 108 Form 4 filings, the earliest from 2 October 2024. InsiderAlpha adds new Form 4, Form 144 and 8-K filings as they arrive from SEC EDGAR.
How many insiders are buying MPWR stock?
No insider purchases of MPWR were filed in the last 90 days.
How many insiders are selling MPWR stock?
14 insider sales of MPWR were filed in the last 90 days, totaling $40.72M.
Where can I see MPWR SEC filings (Form 4, 10-K, 10-Q, 8-K)?
This page collects MPWR Form 4 insider transactions, Form 144 sale notices and 8-K filings in one place. Annual 10-K and quarterly 10-Q reports live on the company's SEC EDGAR page.
More Information Technology companies with insider activity
House of Representatives Periodic Transaction Reports from 2024. Senate filings are not included yet. The full history of MPWR beside its insider purchases is in the Congress Tracker.
Michael Hsing - OfficerOpen-market sale$789K
Theodore Blegen - Officer
Carintia Martinez
Byron DonaldsRepublican, FL-19
