MONOLITHIC POWER SYSTEMS INC·4

May 20, 8:10 PM ET

Hsing Michael 4

4 · MONOLITHIC POWER SYSTEMS INC · Filed May 20, 2026

Research Summary

AI-generated summary of this filing

Updated

Monolithic Power Systems (MPWR) CEO Michael Hsing Sells 40,000 Shares

What Happened
Michael Hsing, CEO and a director of Monolithic Power Systems (MPWR), sold a total of 40,000 shares in a series of open-market transactions on May 18, 2026. The individual trades ranged in price roughly from $1,460 to $1,521 per share, generating aggregate proceeds of approximately $59.31 million. These were sales (code S) — not purchases or option exercises.

Key Details

  • Transaction date: May 18, 2026; Form 4 filed May 20, 2026 (filed within the normal two-business-day window).
  • Total shares sold: 40,000; Total proceeds: ~$59,310,170.
  • Price range across the trades: approximately $1,459.96 to $1,521.56 per share (footnotes give weighted-average price ranges for the individual reported lines).
  • Shares owned after transaction: not specified in the provided lines; footnote F1 notes the ending balance includes 29 shares acquired Feb 17, 2026 via the company ESPP.
  • Notes/footnotes: Multiple footnotes (F2–F14) indicate the reported line prices are weighted averages and that the filer can provide the exact number of shares sold at each separate price upon request.

Context

  • These were open-market sales (routine dispositions) rather than purchases or option exercises; such sales frequently reflect liquidity or diversification decisions rather than direct commentary on company fundamentals.
  • No indication in the filing of gifts, exercises, or tax-withholding shares; all reported items are sales (S).
  • Filing appears timely (not marked late).

Insider Transaction Report

Form 4
Period: 2026-05-18
Hsing Michael
DirectorCEO
Transactions
  • Sale

    Common Stock

    [F2][F1]
    2026-05-18$1462.61/sh3,424$5,007,977884,839 total
  • Sale

    Common Stock

    [F3]
    2026-05-18$1467.62/sh5,819$8,540,081879,020 total
  • Sale

    Common Stock

    [F4]
    2026-05-18$1472.84/sh5,049$7,436,369873,971 total
  • Sale

    Common Stock

    [F5]
    2026-05-18$1476.96/sh4,082$6,028,951869,889 total
  • Sale

    Common Stock

    [F6]
    2026-05-18$1482.51/sh5,737$8,505,160864,152 total
  • Sale

    Common Stock

    [F7]
    2026-05-18$1486.76/sh6,688$9,943,451857,464 total
  • Sale

    Common Stock

    [F8]
    2026-05-18$1491.48/sh862$1,285,656856,602 total
  • Sale

    Common Stock

    [F9]
    2026-05-18$1499.46/sh608$911,672855,994 total
  • Sale

    Common Stock

    [F10]
    2026-05-18$1503.05/sh2,929$4,402,433853,065 total
  • Sale

    Common Stock

    [F11]
    2026-05-18$1507.70/sh3,769$5,682,521849,296 total
  • Sale

    Common Stock

    [F12]
    2026-05-18$1513.11/sh551$833,724848,745 total
  • Sale

    Common Stock

    [F13]
    2026-05-18$1518.15/sh352$534,389848,393 total
  • Sale

    Common Stock

    [F14]
    2026-05-18$1521.43/sh130$197,786848,263 total
Holdings
  • Common Stock

    (indirect: By Trust)
    133,040
  • Common Stock

    (indirect: By Trust)
    12,825
Footnotes (14)
  • [F1]Ending balance includes 29 shares acquired on February 17, 2026 through the Company's qualified ESPP program.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $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.
  • [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 $,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.
Signature
/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing|2026-05-20

Documents

1 file
  • 4
    marketforms-73205.xmlPrimary

    PRIMARY DOCUMENT