Sec Form 3 Filing - Castle Angela M @ OLIN Corp - 2025-03-01

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Castle Angela M 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 (Last) (First) (Middle) 16290 KATY FREEWAY, 600 3. Date of Earliest Transaction (MM/DD/YY) 03/01/2025 (Street) HOUSTON, TX77094 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 1,504 D Common Stock 2.331 ( 1 ) I ESOP 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Employee Stock Options (Right to Buy) $ 32.94 02/16/2021 02/16/2029 Common Stock 3,000 D Employee Stock Options (Right to Buy) $ 26.26 02/19/2022 02/19/2030 Common Stock 4,533 D Employee Stock Options (Right to Buy) $ 17.33 02/18/2023 02/18/2031 Common Stock 5,233 D Employee Stock Options (Right to Buy) $ 28.99 02/15/2024 02/15/2032 Common Stock 6,200 D Employee Stock Options (Right to Buy) $ 49.71 02/22/2025 02/22/2033 Common Stock 3,800 D Employee Stock Options (Right to Buy) $ 60.55 ( 2 ) 02/22/2034 Common Stock 1,846 D Employee Stock Options (Right to Buy) $ 52.29 ( 3 ) 02/22/2035 Common Stock 2,483 D Restricted Stock Units ( 5 ) ( 4 ) ( 5 ) Common Stock 10,138 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Castle Angela M 16290 KATY FREEWAY 600 HOUSTON, TX77094 VP & Chief Legal Officer Signatures /s/ E.C Tanner, Attorney-in-Fact 03/10/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )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 March 1, 2025. ( 2 )This option vests in three installments with 1,231 currently exercisable and the remaining 615 vesting on February 22, 2026. ( 3 )This option vests in three installments with 828 currently exercisable as of February 22, 2025 and 828 vesting on February 22, 2026 and 827 vesting on February 22, 2027. ( 4 )Restricted stock units convert into common stock on a one-to-one basis. ( 5 )These restricted stock units vest in three annual installments beginning with 3,380 vesting on February 20, 2026 and 3,379 vesting on February 20, 2027 and 3,379 vesting on February 20, 2028.

Remarks: Exhibit 24.1 - Power of Attorney

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.