FMR LLC has filed an amended Schedule 13G reporting a significant ownership stake in Monolithic Power Systems, Inc. common stock. As of December 31, 2025, FMR LLC and related entities beneficially own 3,977,007.87 shares, representing 8.3% of the company’s outstanding common stock.
FMR LLC has sole voting power over 3,736,527.22 shares and sole dispositive power over 3,977,007.87 shares. Abigail P. Johnson is reported with sole dispositive power over the same 3,977,007.87 shares, but no voting power. The filing states the shares are held in the ordinary course of business and not for the purpose of changing or influencing control, and that various underlying clients have rights to dividends or sale proceeds, with no single client holding more than five percent.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 2)
MONOLITHIC POWER SYSTEMS INC
(Name of Issuer)
COMMON STOCK
(Title of Class of Securities)
609839105
(CUSIP Number)
12/31/2025
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
SCHEDULE 13G
CUSIP No.
609839105
1
Names of Reporting Persons
FMR LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
3,736,527.22
6
Shared Voting Power
0.00
7
Sole Dispositive Power
3,977,007.87
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,977,007.87
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
8.3 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
CUSIP No.
609839105
1
Names of Reporting Persons
Abigail P. Johnson
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
3,977,007.87
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,977,007.87
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
8.3 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
MONOLITHIC POWER SYSTEMS INC
(b)
Address of issuer's principal executive offices:
5808 LAKE WASHINGTON BLVD. NE,KIRKLAND,WA,USA,98033
Item 2.
(a)
Name of person filing:
FMR LLC
(b)
Address or principal business office or, if none, residence:
245 Summer Street, Boston, Massachusetts 02210
(c)
Citizenship:
Not applicable
(d)
Title of class of securities:
COMMON STOCK
(e)
CUSIP No.:
609839105
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
3977007.87
(b)
Percent of class:
8.3 %
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
Please see the responses to Items 5 and 6 on the cover page.
(ii) Shared power to vote or to direct the vote:
0.00
(iii) Sole power to dispose or to direct the disposition of:
3977007.87
(iv) Shared power to dispose or to direct the disposition of:
0.00
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
One or more other persons are known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the COMMON STOCK of MONOLITHIC POWER SYSTEMS INC. No one other person's interest in the COMMON STOCK of MONOLITHIC POWER SYSTEMS INC is more than five percent of the total outstanding COMMON STOCK.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
See attached Exhibit 99.
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above 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 of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
FMR LLC
Signature:
Stephanie J. Brown
Name/Title:
Duly authorized under Power of Attorney effective as of January 3, 2023, by and on behalf of FMR LLC and its direct and indirect subsidiaries*
Date:
02/04/2026
Abigail P. Johnson
Signature:
Stephanie J. Brown
Name/Title:
Duly authorized under Power of Attorney effective as of January 26, 2023, by and on behalf of Abigail P. Johnson**
Date:
02/04/2026
Comments accompanying signature: * This power of attorney is incorporated herein by reference to Exhibit 24 to the Schedule 13G filed by FMR LLC on January 10, 2023, accession number: 0000315066-23-000003. ** This power of attorney is incorporated herein by reference to Exhibit 24 to the Schedule 13G filed by FMR LLC on January 31, 2023, accession number: 0000315066-23-000038.
What stake does FMR LLC report in Monolithic Power Systems (MPWR)?
FMR LLC reports beneficial ownership of 3,977,007.87 Monolithic Power Systems shares, or 8.3% of the common stock. This reflects a sizable institutional position disclosed in an amended Schedule 13G as of December 31, 2025.
How much voting power does FMR LLC have in MPWR according to the Schedule 13G/A?
FMR LLC reports sole voting power over 3,736,527.22 MPWR common shares and no shared voting power. This indicates FMR can vote these shares independently, while the remaining beneficially owned shares are not reported with voting authority.
What is Abigail P. Johnson’s reported beneficial ownership in MPWR?
Abigail P. Johnson is reported as beneficially owning 3,977,007.87 MPWR shares, or 8.3% of the class, with sole dispositive power. The filing shows she has no voting power or shared authority over these Monolithic Power Systems shares.
Are MPWR shares held by FMR LLC intended to influence control of the company?
The filing states the MPWR shares were acquired and are held in the ordinary course of business, not to change or influence control. It also notes they are not held in connection with any transaction aimed at controlling Monolithic Power Systems.
Who ultimately receives dividends or sale proceeds from FMR’s MPWR holdings?
The filing notes that one or more other persons have rights to receive dividends or sale proceeds from the MPWR shares. These are underlying clients of FMR-related entities, and no single such person has more than five percent of the class.
What type of filing did FMR LLC submit for its MPWR ownership?
FMR LLC submitted an Amendment No. 2 to Schedule 13G for Monolithic Power Systems common stock. A Schedule 13G is a beneficial ownership report used primarily by institutional or passive investors holding more than five percent of a class.
