Olin (OLN) legal chief Castle nets stock sale after 3,380 RSUs vest

Rhea-AI Filing Summary

Olin Corporation VP & Chief Legal Officer Angela M. Castle reported several equity moves. On February 24, 2026, she sold 2,379.2625 shares of common stock in open-market transactions at a weighted average price of $24.2512, within a $24.22–$24.3415 range. On February 20, 2026, 3,380 restricted stock units were converted into the same number of common shares at $0, with 1,003 shares withheld at $24.09 to cover taxes. Following these transactions, she directly held 1,527.7375 common shares, 6,758 restricted stock units, and indirectly held 2.4123 shares through the Olin Corporation Retirement Savings Plan.

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).

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^*

Castle Angela M

(Last) (First) (Middle)

16290 KATY FREEWAY

600

(Street)

HOUSTON TX 77094

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
OLIN Corp [ OLN ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	VP & Chief Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/20/2026

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	02/20/2026		M		3,380	A	(1)	4,910	D
Common Stock	02/20/2026		F		1,003	D	$24.09	3,907	D
Common Stock	02/24/2026		S		2,379.2625	D	$24.2512(2)	1,527.7375	D
Common Stock								2.4123(3)	I	By RSP Trustee

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
Restricted Stock Units	(1)	02/20/2026		M			3,380	(4)	(4)	Common Stock	3,380	$0	6,758	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of Olin Common Stock.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.22 to $24.3415, inclusive. The reporting person undertakes to provide to Olin Corporation, any security holder of Olin Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote 2 to this Form 4.

3. The figure represents shares of Olin Common Stock held under the Olin Corporation Retirement Savings Plan, a tax conditioned plan reflecting transactions exempt under Rule 16b-3, as reported by the RSP Plan Administrator as of February 20, 2026.

4. On February 20, 2025 the reporting person was granted 10,138 restricted stock units, 3,380 shares vested on February 20, 2026, 3,379 shares vest on February 20, 2027 and 3,379 shares vest on February 20, 2028.

Remarks:

	/s/ E.C Tanner, Attorney-in-Fact	02/24/2026
	** 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 did Olin (OLN) executive Angela M. Castle report in this Form 4?

Angela M. Castle reported an open-market sale of Olin common stock and the vesting and conversion of restricted stock units, along with tax-withholding share dispositions, updating her direct and indirect ownership positions in Olin equity as of late February 2026.

How many Olin (OLN) shares did Angela M. Castle sell in open-market transactions?

She sold 2,379.2625 shares of Olin common stock in open-market transactions at a weighted average price of $24.2512 per share, with individual sale prices ranging between $24.22 and $24.3415, as disclosed in the Form 4 filing footnotes.

What restricted stock unit activity did Angela M. Castle report for Olin (OLN)?

She reported the conversion of 3,380 restricted stock units into the same number of Olin common shares at zero exercise price. These units are part of a larger 10,138-unit grant, with additional tranches scheduled to vest in 2027 and 2028 under the award terms.

How many Olin (OLN) shares were withheld to cover Angela M. Castle’s taxes?

A total of 1,003 Olin common shares were disposed of at $24.09 per share to satisfy tax-withholding obligations tied to the restricted stock unit vesting and conversion, classified in the Form 4 as a tax-withholding disposition rather than an open-market sale.

What is Angela M. Castle’s Olin (OLN) ownership after these transactions?

After the reported transactions, she directly held 1,527.7375 shares of Olin common stock and 6,758 restricted stock units, and indirectly held 2.4123 common shares through the Olin Corporation Retirement Savings Plan, as reported by the plan administrator on February 20, 2026.

How are Angela M. Castle’s indirect Olin (OLN) holdings structured?

Her indirect ownership consists of Olin common stock held under the Olin Corporation Retirement Savings Plan, a tax-conditioned plan. The Form 4 notes 2.4123 shares held there as of February 20, 2026, based on information from the plan administrator.