Michael Hsing - Nov 12, 2025 Form 4 Insider Report for MONOLITHIC POWER SYSTEMS INC (MPWR)

Signature
/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing
Stock symbol
MPWR
Transactions as of
Nov 12, 2025
Transactions value $
-$35,724,380
Form type
4
Date filed
11/13/2025, 04:15 PM
Previous filing
Nov 13, 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Hsing Michael CEO, Director 1555 PALM BEACH LAKES BLVD., WEST PALM BEACH /s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing 2025-11-12 0001308676

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MPWR Common Stock Sale -$386K -403 -0.04% $957.58 955K Nov 12, 2025 Direct F1
transaction MPWR Common Stock Sale -$2.68M -2.8K -0.29% $958.34 952K Nov 12, 2025 Direct F2
transaction MPWR Common Stock Sale -$422K -440 -0.05% $959.36 952K Nov 12, 2025 Direct F3
transaction MPWR Common Stock Sale -$387K -403 -0.04% $960.45 952K Nov 12, 2025 Direct F4
transaction MPWR Common Stock Sale -$1.83M -1.9K -0.2% $961.63 950K Nov 12, 2025 Direct F5
transaction MPWR Common Stock Sale -$2.71M -2.82K -0.3% $962.61 947K Nov 12, 2025 Direct F6
transaction MPWR Common Stock Sale -$3.42M -3.55K -0.38% $963.47 943K Nov 12, 2025 Direct F7
transaction MPWR Common Stock Sale -$3.15M -3.26K -0.35% $964.47 940K Nov 12, 2025 Direct F8
transaction MPWR Common Stock Sale -$5.43M -5.62K -0.6% $965.50 934K Nov 12, 2025 Direct F9
transaction MPWR Common Stock Sale -$6.34M -6.56K -0.7% $966.45 928K Nov 12, 2025 Direct F10
transaction MPWR Common Stock Sale -$2.93M -3.02K -0.33% $967.41 925K Nov 12, 2025 Direct F11
transaction MPWR Common Stock Sale -$2.01M -2.07K -0.22% $968.37 923K Nov 12, 2025 Direct F12
transaction MPWR Common Stock Sale -$945K -975 -0.11% $969.62 922K Nov 12, 2025 Direct F13
transaction MPWR Common Stock Sale -$706K -728 -0.08% $970.29 921K Nov 12, 2025 Direct F14
transaction MPWR Common Stock Sale -$57.3K -59 -0.01% $971.81 921K Nov 12, 2025 Direct F15
transaction MPWR Common Stock Sale -$448K -461 -0.05% $972.78 921K Nov 12, 2025 Direct F16
transaction MPWR Common Stock Sale -$290K -298 -0.03% $973.73 920K Nov 12, 2025 Direct F17
transaction MPWR Common Stock Sale -$620K -633 -0.07% $979.59 920K Nov 12, 2025 Direct F18
transaction MPWR Common Stock Sale -$967K -987 -0.11% $980.06 919K Nov 12, 2025 Direct F19
holding MPWR Common Stock 133K Nov 12, 2025 by M Hsing 04 Trust
holding MPWR Common Stock 12.8K Nov 12, 2025 ZH Family 2020 Trust
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 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 $957.18 to $957.95. 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.
F2 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 $958.06 to $958.88. 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.
F3 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 $959.01 to $959.56. 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.
F4 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 $960.74. 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.
F5 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 $961.07 to $961.98. 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.
F6 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 $962.02 to $962.99. 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.
F7 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 $963.00 to $963.99. 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.
F8 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 $964.92. 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.
F9 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 $965.00 to $965.98. 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.
F10 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 $966.00 to $ 966.99. 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.
F11 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 $967.00 to $967.93. 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.
F12 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 $968.01 to $968.94. 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.
F13 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 $969.14 to $969.98. 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.
F14 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 $970.02 to $970.85. 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.
F15 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 $971.74 to $971.96. 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.
F16 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 $972.05 to $972.98. 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.
F17 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 $973.45 to $973.84. 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.
F18 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 $979.59 to $979.60. 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.
F19 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 $980.00 to $980.25. 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.