Monolithic Power (NASDAQ: MPWR) CEO executes Rule 10b5-1 stock sales

Rhea-AI Filing Summary

Monolithic Power Systems CEO Michael Hsing reported a series of open-market sales of company common stock on February 12, 2026. The Form 4 shows multiple sale transactions at prices ranging from $1,155.71 to $1,217.12 per share, including 12,731 shares at $1,155.71 and 4,992 shares at $1,159.84.

After these sales, Hsing held 888,234 shares directly. He also had indirect beneficial ownership of 133,040 shares through the M Hsing 04 Trust and 12,825 shares through the ZH Family 2020 Trust. The filing notes the transactions were made under a Rule 10b5-1 trading plan adopted on August 28, 2025.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Hsing Michael

(Last) (First) (Middle)

1555 PALM BEACH LAKES BLVD.

(Street)

WEST PALM BEACH FL 33401

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MONOLITHIC POWER SYSTEMS INC [ MPWR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/12/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/12/2026		S		12,731(1)	D	$1,155.71(2)	908,503	D
Common Stock	02/12/2026		S		4,992(1)	D	$1,159.84(3)	903,511	D
Common Stock	02/12/2026		S		4,001(1)	D	$1,164.92(4)	899,510	D
Common Stock	02/12/2026		S		2,076(1)	D	$1,168.8(5)	897,434	D
Common Stock	02/12/2026		S		200(1)	D	$1,173.39(6)	897,234	D
Common Stock	02/12/2026		S		480(1)	D	$1,180.79(7)	896,754	D
Common Stock	02/12/2026		S		160(1)	D	$1,188.23(8)	896,594	D
Common Stock	02/12/2026		S		600(1)	D	$1,194.34(9)	895,994	D
Common Stock	02/12/2026		S		1,440(1)	D	$1,200.81(10)	894,554	D
Common Stock	02/12/2026		S		3,640(1)	D	$1,205.82(11)	890,914	D
Common Stock	02/12/2026		S		1,240(1)	D	$1,210.11(12)	889,674	D
Common Stock	02/12/2026		S		1,440(1)	D	$1,217.12(13)	888,234	D
Common Stock								133,040	I	by M Hsing 04 Trust
Common Stock								12,825	I	ZH Family 2020 Trust

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 08/28/2025.

2. 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 $1,152.31 to $1,157.31. 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.

3. 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 $1,157.38 to $1,162.38. 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.

4. 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 $1,162.42 to $1,167.20 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.

5. 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 $1,167.43 to $1,172.17. 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.

6. 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 $1,172.82 to $1,175.07. 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.

7. 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 $1,179.43 to $1,182.24. 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.

8. 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 $1,185.94 to $1,190.48. 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.

9. 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 $1,191.26 to $1,195.35. 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.

10. 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 $1,197.57 to $1,202.33. 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.

11. 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 $1,202.70 to $1,207.63. 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.

12. 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 $1,207.93 to $1,212.36. 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.

13. 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 $1,214.09 to $1,218.82. 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.

Remarks:

	/s/ Saria Tseng, attorney-in-fact for Mr. Michael R. Hsing	02/17/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did MPWR CEO Michael Hsing report on February 12, 2026?

Michael Hsing reported multiple open-market sales of Monolithic Power Systems common stock on February 12, 2026. The trades were executed at prices between about $1,155.71 and $1,217.12 per share, with several distinct sale blocks disclosed in the Form 4.

How many Monolithic Power Systems (MPWR) shares does Michael Hsing own after the reported sales?

After the reported sales, Michael Hsing directly owned 888,234 MPWR shares. He also had indirect beneficial ownership of 133,040 shares through the M Hsing 04 Trust and 12,825 shares through the ZH Family 2020 Trust, as disclosed in the Form 4.

At what prices did MPWR CEO Michael Hsing sell his Monolithic Power shares?

The reported sales occurred at weighted average prices from $1,155.71 to $1,217.12 per share. Each line in the filing includes a specific average price and a stated range of individual sale prices underlying that weighted average for the grouped transactions.

Were Michael Hsing’s MPWR stock sales made under a pre-arranged trading plan?

Yes. The Form 4 states the transactions were made under a Rule 10b5-1 trading plan adopted by Michael Hsing on August 28, 2025. Such plans allow insiders to schedule trades in advance, providing structure around timing of transactions.

What role does Michael Hsing hold at Monolithic Power Systems (MPWR)?

Michael Hsing is identified in the filing as both a director and an officer of Monolithic Power Systems, serving as CEO. His dual role means his stock transactions are closely tracked and must be reported on Form 4 under Section 16 rules.

Does the Form 4 for MPWR indicate any derivative security transactions by Michael Hsing?

No derivative security transactions are listed for Michael Hsing in the provided Form 4 excerpt. Table II, which would cover options or other derivatives, contains no specific entries, while all reported activity involves non-derivative common stock sales.