[Form 4] POWER SOLUTIONS INTERNATIONAL, INC. Insider Trading Activity

Rhea-AI Filing Summary

Power Solutions International insiders reported coordinated sales of 79,839 shares on 09/11/2025, reducing their indirect stake to 10,599,759 shares. The Form 4 is filed jointly by Weichai America Corp., Weichai Power Co., Ltd. and Shandong Heavy Industry Group Co., Ltd., each identified as a director and 10% owner. The sales were executed pursuant to broker-dealer transactions under Rule 144 and were reported as multiple trades at weighted average prices across four ranges from about $91.36 to $94.98 per share. The report clarifies that Weichai America Corp. is the direct owner and the Reporting Persons share voting and dispositive power over the reported shares.

Positive

• Compliance with disclosure rules: The Reporting Persons filed a joint Form 4 and provided explanatory footnotes and exhibit references.
• Transparency on transaction method: Sales were identified as Rule 144 broker-dealer transactions with price ranges disclosed.

Negative

• Material insider sales: Reporting Persons disposed of 79,839 shares on 09/11/2025, which reduces their stake though they remain major holders.
• Concentrated indirect ownership: The entities continue to hold a substantial indirect position of 10,599,759 shares, which may concentrate control.

Insights

Financial Analyst

TL;DR: Insiders sold 79,839 shares via Rule 144; total indirect holdings remain above 10.5 million shares.

The Form 4 documents aggregated broker-dealer sales totaling 79,839 shares on a single date, 09/11/2025, executed under Rule 144. Reported weighted average prices fall within specified ranges from $91.36 to $94.98, indicating multiple tranche sales rather than a single block trade. The sellers are affiliated entities that jointly report shared voting and dispositive power; Weichai America Corp. is the direct owner. From an investor-data perspective, these are disclosure-driven transactions without additional financial metrics provided.

Corporate Governance Expert

TL;DR: Joint filing shows coordinated disposition by related reporting persons; control remains collective rather than individual.

The filing is a joint Form 4 by three related entities, each marked as a director and 10% owner, which highlights coordinated compliance with Section 16 reporting. The explanation states no individual has beneficial ownership and that the entities share voting and dispositive powers, which is material for governance transparency. The report includes incorporated powers of attorney exhibits referenced from prior filings, supporting authorized signatures dated 09/15/2025.

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

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

1. Name and Address of Reporting Person^*

Weichai America Corp.

(Last) (First) (Middle)

3100 GOLF ROAD

(Street)

ROLLING MEADOWS IL 60008

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
POWER SOLUTIONS INTERNATIONAL, INC. [ PSIX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/11/2025

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

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

	Form filed by One Reporting Person
X	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	09/11/2025		S(1)		6,738	D	$91.7162(2)	10,672,860	I	See Explanation of Responses(6)
Common Stock	09/11/2025		S(1)		19,351	D	$92.4591(3)	10,653,509	I	See Explanation of Responses(6)
Common Stock	09/11/2025		S(1)		23,231	D	$93.6446(4)	10,630,278	I	See Explanation of Responses(6)
Common Stock	09/11/2025		S(1)		30,519	D	$94.3281(5)	10,599,759	I	See Explanation of Responses(6)

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

1. Name and Address of Reporting Person^*

Weichai America Corp.

(Last) (First) (Middle)

3100 GOLF ROAD

(Street)

ROLLING MEADOWS IL 60008

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Weichai Power Co., Ltd.

(Last) (First) (Middle)

SECTION A 197, FU SHOU EAST STREET

HIGH-TECH INDUSTRIAL DEV. ZONE

(Street)

WEIFANG, SHANDONG PROVINCE F4 261061

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Shandong Heavy Industry Group Co., Ltd.

(Last) (First) (Middle)

#40-1 YANZI SHAN WEST ROAD

(Street)

JINAN, SHANDONG PROVINCE F4 250014

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. These transactions occurred pursuant to broker-dealer sales conducted in accordance with Rule 144 under the Securities Act of 1933, as amended.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.36 to $91.99, inclusive. The Reporting Persons (as defined below) undertake to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares of Common Stock sold at each separate price within the range set forth in this footnote.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.00 to $92.97, inclusive. The Reporting Persons (as defined below) undertake to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares of Common Stock sold at each separate price within the range set forth in this footnote.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.00 to $93.99, inclusive. The Reporting Persons (as defined below) undertake to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares of Common Stock sold at each separate price within the range set forth in this footnote.

5. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $94.00 to $94.98, inclusive. The Reporting Persons (as defined below) undertake to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares of Common Stock sold at each separate price within the range set forth in this footnote.

6. This report is filed jointly by Weichai America Corp., Weichai Power Co., Ltd. and Shandong Heavy Industry Group Co., Ltd. (collectively, the "Reporting Persons"). Weichai America Corp. is the direct owner of the Common Stock referenced in this report and shares the power to vote and the power to dispose of all of such shares of Common Stock with the other Reporting Persons. No individual has beneficial ownership over the Common Stock beneficially owned by the Reporting Persons.

Remarks:

Exhibit List: Exhibit 24.1 - Power of Attorney (Weichai Power Co., Ltd.), incorporated by reference to Exhibit 24.1 to the Form 4 filed by Reporting Persons with the Securities and Exchange Commission on August 14, 2025 Exhibit 24.2 - Power of Attorney (Shandong Heavy Industry Group Co., Ltd.), incorporated by reference to Exhibit 24.2 to the Form 4 filed by Reporting Persons with the Securities and Exchange Commission on August 14, 2025

	/s/ Jinguang Liu (aka Jin Liu), Chief Financial Officer, Weichai America Corp.	09/15/2025
	/s/ Chenglong Sun, Authorized Representative, Weichai Power Co., Ltd.	09/15/2025
	/s/ Chenglong Sun, Authorized Representative, Shandong Heavy Industry Group Co., Ltd.	09/15/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What did insiders file on Form 4 for PSIX on 09/11/2025?

The filing reports broker-dealer sales totaling 79,839 shares of PSIX executed on 09/11/2025 and later reported on the Form 4.

Who are the reporting persons on this PSIX Form 4?

The Form 4 is filed jointly by Weichai America Corp., Weichai Power Co., Ltd., and Shandong Heavy Industry Group Co., Ltd., each identified as a director and 10% owner.

At what prices were the PSIX shares sold according to the Form 4?

Sales were reported as weighted average prices within ranges: approximately $91.36–$91.99, $92.00–$92.97, $93.00–$93.99, and $94.00–$94.98 per footnotes.

How many PSIX shares do the reporting persons hold after the transactions?

Following the reported transactions, the Reporting Persons beneficially own an indirect total of 10,599,759 shares as stated in the Form 4.

Were the sales executed under a specific exemption or rule?

Yes, the transactions were executed pursuant to Rule 144 under the Securities Act of 1933, as stated in the filing.