[Form 4/A] INNOSPEC INC. Amended Insider Trading Activity

Rhea-AI Filing Summary

INNOSPEC INC. director Milton C. Blackmore reported amended details of recent stock sales. On February 27, 2026, he completed two open-market sales of the company’s common stock totaling 594 shares. One block of 287 shares was sold at a weighted average price of $76.30 per share, and another 307 shares at a weighted average price of $76.79 per share. After these transactions, his directly held stake changed in two steps to 10,837 shares and then 10,530 shares of common stock. This amended Form 4 corrects previously reported transaction prices and notes that the sale prices reflect weighted averages across multiple trades within stated ranges.

Insider Trade Summary

Net Seller: 594 shares ($45,473)

Net Sell 2 txns

Insider Blackmore Milton C

Role Director

Sold 594 shs ($45K)

Type	Security	Shares	Price	Value
Sale	Common Stock	287	$76.30	$22K
Sale	Common Stock	307	$76.79	$24K

Holdings After Transaction: Common Stock — 10,837 shares (Direct)

Footnotes (1)

1. This Form 4/A amends the Form 4 filed on March 3, 2026 to correct the transaction price reported in Table I. The price reported reflects the weighted average sale price. The shares were sold in multiple transactions at prices ranging from $75.5001 to $76.55. The reporting person undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. This Form 4/A amends the Form 4 filed on March 3, 2026 to correct the transaction price reported in Table I. The price reported reflects the weighted average sale price. The shares were sold in multiple transactions at prices ranging from $76.555 to $77.0713. The reporting person undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Blackmore Milton C

(Last) (First) (Middle)

8310 SOUTH VALLEY HIGHWAY

SUITE 350

(Street)

ENGLEWOOD CO 80112

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
INNOSPEC INC. [ IOSP ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)
03/03/2026

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	02/27/2026		S		287	D	$76.3(1)	10,837	D
Common Stock	02/27/2026		S		307	D	$76.79(2)	10,530	D

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. This Form 4/A amends the Form 4 filed on March 3, 2026 to correct the transaction price reported in Table I. The price reported reflects the weighted average sale price. The shares were sold in multiple transactions at prices ranging from $75.5001 to $76.55. The reporting person undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

2. This Form 4/A amends the Form 4 filed on March 3, 2026 to correct the transaction price reported in Table I. The price reported reflects the weighted average sale price. The shares were sold in multiple transactions at prices ranging from $76.555 to $77.0713. The reporting person undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

	Milton C. Blackmore	03/06/2026
	** 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 INNOSPEC (IOSP) report for Milton C. Blackmore?

INNOSPEC director Milton C. Blackmore reported amended details of two open-market stock sales totaling 594 common shares on February 27, 2026. The filing corrects previously reported prices and confirms the transactions were executed in multiple trades at weighted average sale prices within stated ranges.

How many INNOSPEC (IOSP) shares did Milton C. Blackmore sell and at what prices?

Milton C. Blackmore sold 287 INNOSPEC shares at a weighted average price of $76.30 and 307 shares at a weighted average price of $76.79. Both sales were open-market transactions executed through multiple trades within specified price ranges.

What was Milton C. Blackmore’s INNOSPEC (IOSP) ownership after these Form 4/A sales?

Following the first sale, Milton C. Blackmore directly held 10,837 INNOSPEC common shares, and after the second sale, his direct holdings were 10,530 shares. The filing specifies these are direct ownership positions, reflecting his remaining stake after the reported transactions.

Why was this INNOSPEC (IOSP) Form 4/A filed as an amendment?

The Form 4/A was filed to correct the transaction prices originally reported. It clarifies that the prices shown are weighted average sale prices from multiple trades and offers to provide full trade-by-trade details, including exact share counts and prices, upon request to interested parties.

What price ranges are disclosed for Milton C. Blackmore’s INNOSPEC (IOSP) stock sales?

The filing states one group of sales occurred at prices ranging from $75.5001 to $76.55, and another group ranged from $76.555 to $77.0713. The reported per-share prices in the tables represent weighted averages across these multiple individual trades.