UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

RULE 13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No. 6)*

LSB Industries, Inc.

(Name of Issuer)

Common Stock, par value $0.10 per share

(Title of Class of Securities)

502160104

(CUSIP Number)

Anthony D. Minella

c/o LSB Funding LLC Legal Department

600 Steamboat Road

Greenwich, CT 06830

1-800-224-6469

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 15, 2022

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box.  ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on following pages)

SCHEDULE 13D

CUSIP No. 502160104

This statement on Schedule 13D (this “Statement”) relates to the common stock, par value $0.10 per share (the “Common Stock”) of LSB Industries, Inc., a Delaware corporation (the “Issuer”). The address of the principal executive offices of the Issuer is 3503 NW 63rd Street, Suite 500, Oklahoma City, Oklahoma 73116.

This Statement represents Amendment No. 6 to the Schedule 13D (the “Original Schedule 13D”), originally filed with the Securities and Exchange Commission (the “SEC”) by LSB Funding LLC, a Delaware limited liability company (the “Reporting Person”) on December 14, 2015, and amended by Amendment No. 1 to the Schedule 13D (the “Amendment No. 1”), originally filed with the SEC by the Reporting Person on May 20, 2016, amended by Amendment No. 2 to the Schedule 13D (the “Amendment No. 2”), originally filed with the SEC by the Reporting Person on July 20, 2021, amended by Amendment No. 3 to the Schedule 13D (the “Amendment No. 3”), originally filed with the SEC by the Reporting Person on September 27, 2021, amended by Amendment No. 4 to the Schedule 13D (the “Amendment No. 4”), originally filed with the SEC by the Reporting Person on October 12, 2021, and amended by Amendment No. 5 to the Schedule 13D (the “Amendment No. 5”), originally filed with the SEC by the Reporting Person on August 10, 2022

All capitalized terms not otherwise defined herein have the meanings set forth in the Original Schedule 13D, Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4 or Amendment No. 5 as applicable.

Item 4 is hereby amended to add the following:

Underwriting Agreement

On August 10, 2022, the Reporting Person and SBT Investors LLC (“SBT Investors”) (collectively the “Selling Stockholders”), entered into an underwriting agreement (the “Underwriting Agreement”) with the Issuer and Goldman Sachs & Co. LLC and UBS Securities LLC, as the representatives of the several underwriters (the “Underwriters”), pursuant to which the Underwriters agreed to purchase an aggregate of 13,500,000 shares of Common Stock from the Selling Stockholders (the “Public Equity Offering”) with an option to purchase up to 1,200,000 additional shares of Common Stock from the Selling Stockholders (the “Option”), each at a price of $12.3175 per share. The Underwriters gave notice on August 12, 2022 to the Selling Stockholders of their intention to exercise the Option in full. The Public Equity Offering closed on August 15, 2022, and the Option closed on August 16, 2022. The Selling Stockholders sold the following number of shares of Common Stock in aggregate pursuant to the Underwriting Agreement:

Simultaneously upon the closing of the Public Equity Offering, the Issuer repurchased 5,500,000 shares of its Common Stock from the Underwriters at a price per share equal to the price per share paid by the Underwriters to the Selling Stockholders in the Public Equity Offering and the Option.

Lock-up Agreement

In connection with the Underwriting Agreement, each of the Selling Stockholders entered into a 120-day lock-up agreement (the “Lock-up Agreement”) with the Underwriters.

The descriptions of the Underwriting Agreement and Lock-up Agreement are summaries only and are qualified in their entirety by reference to the texts of the Underwriting Agreement and Lock-up Agreement, which are referenced as Exhibit 1 and Exhibit 2 to this Statement. The Underwriting Agreement is incorporated by reference to Exhibit 1.1 to the Current Report on Form 8-K filed by the Issuer with the SEC on August 15, 2022.

Sections (a), (b) and (c) of Item 5 are hereby amended and restated in their entirety as follows:

(a), (b) Based upon the Issuer’s Registration Statement filed on August 10, 2022, there were 88,726,177 shares of Common Stock outstanding as of August 9, 2022. On August 15, 2022, the Reporting Person sold 6,750,00 shares of Common Stock in the Public Equity Offering and the Issuer repurchased 5,500,000 shares of its Common Stock. On August 16, 2022, the Reporting Person sold 600,000 additional shares of Common Stock to the Underwriters pursuant to the exercise of the Option. Accordingly, the Reporting Person beneficially owns 17,650,000 shares of Common Stock, representing approximately 21.2% of the outstanding Common Stock. The Reporting Person has sole voting and dispositive power over such shares.

(c) On August 10, 2022, the Reporting Person made a pro rata distribution in kind, without consideration, of 29,356,127 shares of Common Stock (the “Distributed Shares”) to its indirect equityholders, certain of whom then made a pro rata distribution in kind, without consideration, of a total of 24,803,398 shares of Common Stock to its indirect equityholder SBT Investors, in each case as such indirect equityholder’s member (collectively, the “Distribution”).

Item 6 of the Schedule 13D is hereby amended and supplemented as follows:

The descriptions of the contracts with respect to the Public Equity Offering and the Option set forth in Item 4 are incorporated herein by reference.

SIGNATURES

After reasonable inquiry and to the best of each of the undersigned’s knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

Date: August 16, 2022

EXHIBIT INDEX

Exhibit 2

LSB Industries, Inc.

Lock-Up Agreement

August 10, 2022

Goldman Sachs & Co. LLC

UBS Securities LLC

c/o Goldman Sachs & Co. LLC

200 West Street

New York, New York 10282-2198

c/o UBS Securities LLC

1285 Avenue of the Americas

New York, New York 10019

Re: LSB Industries, Inc. - Lock-Up Agreement

Ladies and Gentlemen:

The undersigned understands that Goldman, Sachs & Co. LLC and UBS Securities LLC, as representatives (the “Representatives”), propose to enter into an underwriting agreement (the “Underwriting Agreement”) on behalf of the several Underwriters named in Schedule II to such agreement (collectively, the “Underwriters”) with LSB Industries, Inc., a Delaware corporation (the “Company,”) and the selling stockholders named therein (the “Selling Stockholders”) providing for a public offering (the “Offering”) of shares of Common Stock, par value $0.10 per share (the “Common Stock”) of the Company (the “Shares”) pursuant to a Registration Statement on Form S-3 filed with the Securities and Exchange Commission (the “SEC”).

In consideration of the agreement by the Underwriters to offer and sell the Shares, and of other good and valuable consideration the receipt and sufficiency of which is hereby acknowledged, the undersigned agrees that, during the period beginning from the date hereof and continuing to and including the date 120 days after the date of the final prospectus supplement used to sell the Shares (the “Lock-Up Period”), the undersigned shall not, and shall not cause or direct any of its affiliates to, (i) offer, sell, contract to sell, pledge, grant any option to purchase, lend or otherwise dispose of any shares of Common Stock of the Company, or any options or warrants to purchase any shares of Common Stock of the Company, or any securities convertible into, exchangeable for or that represent the right to receive shares of Common Stock of the Company (such options, warrants or other securities, collectively, “Derivative Instruments”), including without limitation any such shares or Derivative Instruments now owned or hereafter acquired by the undersigned (collectively, the “Securities”), (ii) engage in any hedging or other transaction or arrangement (including, without limitation, any short sale or the purchase or sale of, or entry into, any put or call option, or combination thereof, forward, swap or any other derivative transaction or instrument, however described or defined) which is designed to or which reasonably could be expected to lead to or result in a sale, loan, pledge or other disposition (whether by the undersigned or someone other than the undersigned), or transfer of any of the economic consequences of ownership, in whole or in part, directly or indirectly, of the Securities, whether any such transaction or arrangement (or instrument provided for thereunder) would be settled by delivery of Common Stock or other securities, in cash or otherwise (any such sale, loan, pledge or other disposition, or transfer of economic consequences, a “Transfer”) or (iii) otherwise publicly announce any intention to engage in or cause any action or activity described in clause (i) above or transaction or arrangement

described in clause (ii) above. The undersigned represents and warrants that, other than as previously disclosed to the Representatives, the undersigned is not, and has not caused or directed any of its affiliates to be or become, currently a party to any agreement or arrangement that provides for, is designed to or which reasonably could be expected to lead to or result in any Transfer during the Lock-Up Period. For the avoidance of doubt, the undersigned agrees that the foregoing provisions shall be equally applicable to any Shares the undersigned may purchase in the Offering.

Notwithstanding the foregoing, the undersigned may transfer the undersigned’s Securities:

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For purposes of this Lock-Up Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin. In addition, notwithstanding the foregoing, if the undersigned is a corporation or other entity, the corporation or such other entity may transfer the Securities to any wholly-owned subsidiary of such corporation or other entity;

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provided, however, that in any such case, it shall be a condition to the transfer that the transferee execute an agreement stating that the transferee is receiving and holding such Securities subject to the provisions of this Agreement and there shall be no further transfer of such Securities except in accordance with this Agreement; and provided, further, that any such transfer shall not involve a disposition for value. The undersigned now has, and, except as permitted by clauses (i)-(x) above, for the duration of this Lock-Up Agreement will have, good and marketable title to the undersigned’s Securities, free and clear of all liens, encumbrances, and claims whatsoever. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the undersigned’s Securities except in compliance with the foregoing restrictions.

The undersigned acknowledges and agrees that the Underwriters have not provided any recommendation or investment advice nor have the Underwriters solicited any action from the undersigned with respect to the Offering of the Shares and the undersigned has consulted their own legal, accounting, financial, regulatory and tax advisors to the extent deemed appropriate. The undersigned further acknowledges and agrees that, although the Underwriters may provide certain Regulation Best Interest and Form CRS disclosures or other related documentation to you in connection with the Offering, the Underwriters are not making a recommendation to you to participate in the Offering or sell any Shares at the price determined in the Offering, and nothing set forth in such disclosures or documentation is intended to suggest that any Underwriter is making such a recommendation.

The restrictions described in this Lock-Up Agreement shall not apply to (i) the sale of the undersigned’s Shares pursuant to the Underwriting Agreement (including the Share Repurchase (as defined in the Underwriting Agreement)); (ii) any sales made pursuant to a trading plan adopted pursuant to Rule 10b5-1 of the Exchange Act prior to the date of this Lock-Up Agreement; provided that any filing under Section 16(a) of the Exchange Act that is made in connection with any such sales during the Lock-Up Period shall state that such sales have been executed under a trading plan pursuant to Rule 10b5-1 under the Exchange Act; and/or (iii) the establishment of, and any sales or transfers pursuant to, a trading plan adopted pursuant to Rule 10b5-1 under the Exchange Act on or after the date of this Lock-Up Agreement; provided that no transfers shall occur under such newly established plan during the period beginning from the date hereof and continuing to and including the date 75 days after the date of the final prospectus supplement used to sell the Shares and no public announcement or filing shall be required or voluntarily made by any person in connection therewith other than general disclosure in Company periodic reports to the effect that Company directors and officers may enter into such trading plans from time to time.

The undersigned understands that the Company and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward consummation of the offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors, and assigns.

This Lock-Up Agreement will automatically terminate upon the earliest to occur, if any, of (a) the date that the Company or the undersigned advises Goldman Sachs & Co. LLC and UBS Securities LLC, in writing, prior to the execution of the Underwriting Agreement, that it has determined not to proceed with the Offering, (b) the date that Goldman Sachs & Co. LLC and UBS Securities LLC advise the Company and the undersigned, in writing, prior to the execution of the Underwriting Agreement, that they have determined not to proceed with the Offering (c) the date of termination of the Underwriting Agreement if prior to the closing of the Offering, or (d) August 31, 2022 if the Offering of the Shares has not been completed by such date. This Lock-Up Agreement shall be governed by and construed in accordance with the laws of the State of New York.

[Signature Page Follows]

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Very truly yours,

[Signature Page to Lock-Up Agreement]