FMR LLC and Abigail P. Johnson filed Amendment No. 4 to Schedule 13G with the SEC on November 4, 2026, disclosing their beneficial ownership of common stock in Monolithic Power Systems Inc as of September 30, 2026.

Key Highlights

  • Aggregate beneficial ownership: FMR LLC and Abigail P. Johnson each reported beneficial ownership of 4,450,333.75 shares of Monolithic Power Systems common stock.
  • Percent of class: The 4,450,333.75 shares represent 9.1% of the outstanding common stock, according to the filing.
  • Sole voting power (FMR LLC): FMR LLC reported sole voting power over 4,165,785.75 shares, with no shared voting power.
  • Sole dispositive power: Both FMR LLC and Abigail P. Johnson each reported sole dispositive power over 4,450,333.75 shares, with no shared dispositive power.
  • Triggering event date: The date of the event requiring this filing was September 30, 2026.
  • Third-party interests: The filing states that one or more other persons have the right to receive or direct the receipt of dividends or proceeds from the sale of the shares, but no single other person's interest exceeds 5% of the total outstanding common stock.

FMR LLC and Abigail P. Johnson Disclose Ownership Position in Monolithic Power Systems

According to the filing, FMR LLC, a Delaware-organized holding company headquartered at 245 Summer Street, Boston, Massachusetts 02210, submitted Amendment No. 4 to its Schedule 13G regarding common stock of Monolithic Power Systems Inc (NASDAQ:MPWR), identified by CUSIP number 609839105. The amendment was signed on November 4, 2026, with a triggering event date of September 30, 2026. Abigail P. Johnson, a United States citizen, is also named as a reporting person in the filing.

The filing reports that FMR LLC holds sole voting power over 4,165,785.75 shares and sole dispositive power over 4,450,333.75 shares. Abigail P. Johnson is reported to hold sole dispositive power over the same 4,450,333.75 shares, with zero sole or shared voting power attributed to her individually. Both reporting persons disclose zero shared voting power and zero shared dispositive power. The aggregate amount beneficially owned by each reporting person is listed as 4,450,333.75 shares, equaling 9.1% of the class.

The filing certifies that the securities "were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer." The filing also references Exhibit 99 for identification and classification of relevant subsidiaries through which the position is held, as FMR LLC is identified as a parent holding company (type HC) under the applicable SEC rules.

What Was Disclosed

FMR LLC and Abigail P. Johnson filed Amendment No. 4 to Schedule 13G disclosing aggregate beneficial ownership of 4,450,333.75 shares, or 9.1%, of Monolithic Power Systems Inc common stock, as of September 30, 2026.