UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 6)*

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 §§240.13d-1(e), 240.13d-1(f) or 240.13d-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 remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

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).

Item 1. Security and Issuer.

This Amendment No. 6 to Schedule 13D (the “Statement”) is being filed to amend the Statement as originally filed with the Securities and Exchange Commission on February 14, 2022, as amended by Amendment No. 1 dated December 1, 2022, Amendment No. 2 dated January 5, 2023, Amendment No. 3 dated January 11, 2022, Amendment No. 4 dated March 31, 2023 and Amendment No. 5 dated May 1, 2023, with respect to the Class A common shares, par value $0.00005 per share (the “Class A common shares”), of Arco Platform Ltd., an exempted company incorporated in the Cayman Islands (the “Company”), whose principal executive offices are located at Rua Augusta 2840, 9th floor, suite 91, Consolação, São Paulo – SP, 01412-100, Brazil. Except as otherwise provided herein, each Item of the Statement remains unchanged.

Item 2. Identity and Background.

No material change.

Item 3. Source and Amount of Funds or Other Consideration.

Item 3 is amended by adding the following:

The descriptions of the Merger Agreement (as defined below), the Rollover and Support Agreement (as defined below), the GA Equity Commitment Letter (as defined below) and the Interim Investors Agreement (as defined below) are incorporated by reference in this Item 3.

Item 4. Purpose of Transaction.

Item 4 is hereby amended and supplemented as follows:

On August 10, 2023, the Company entered into an agreement and plan of merger, dated August 10, 2023 (the “Merger Agreement”), by and among the Company, Achieve Holdings (“Parent”), an exempted company with limited liability incorporated under the laws of the Cayman Islands and Achieve Merger Sub (“Merger Sub”), an exempted company with limited liability incorporated under the laws of the Cayman Islands and a wholly owned Subsidiary of Parent. Pursuant to the Merger Agreement, and subject to the terms and conditions thereof, at the closing of the transactions contemplated by the Merger Agreement (the “Closing”), Merger Sub will be merged with and into the Company (the “Merger”), with the Company continuing as the surviving company (the “Surviving Company”). Pursuant to the Merger Agreement, and subject to the terms and conditions thereof, at the Closing (A) each common share issued and outstanding immediately prior to the effective time of the Merger, as specified in the Merger Agreement (the “Effective Time”), including any holdback common shares issuable to former shareholders of INCO Limited under the Isaac EPA (as defined in the Merger Agreement), will be cancelled in exchange for the right to receive $14.00 in cash per share without interest (the “Per Share Merger Consideration”), except for (i) common shares beneficially owned by Parent or Merger Sub (including any common shares owned by GA, Dragoneer, the Founders, any of their respective subsidiaries and certain other rollover shareholders, which will be contributed to Parent in exchange for Parent equity immediately prior to the Effective Time) which will be cancelled for no consideration; (ii) common shares owned by the Company or any subsidiary of the Company as treasury shares as of immediately prior to the Effective Time, which shall be cancelled for no consideration; (iii) common shares reserved for issuance, settlement and allocation by the Company upon exercise or vesting of any Company equity awards, which shall be treated as contemplated by Section 2.04 of the Merger Agreement; and (iv) common shares owned by holders who have validly exercised and not effectively withdrawn or lost their rights to dissent from the Merger pursuant to Section 238 of the Companies Law of the Cayman Islands; and (B) each ordinary share of Merger Sub issued and outstanding immediately prior to the Effective time shall be converted into one ordinary share, par value $0.00005 per share, of the Surviving Company. The information disclosed in this paragraph is qualified in its entirety by reference to the Merger Agreement, a copy of which is filed as Exhibit 6 and is incorporated herein by reference.

Following the consummation of the Merger, the Company will become a wholly owned subsidiary of Parent and the 2028 Convertible Notes will become obligations of Parent. In addition, if the Merger is consummated, the Class A common shares will be delisted from the NASDAQ Global Select Market, the Company’s obligations to file periodic reports under the Exchange Act will be terminated

and the Company will be privately held by GA, Dragoneer, the Founders (collectively, the “Consortium”) and certain other rollover shareholders.

The Consortium anticipates that approximately US$474,585,909 is expected to be expended to complete the Merger. This amount includes (a) the estimated funds required by Parent to (i) purchase the outstanding Class A common shares not owned by members of the Consortium at a purchase price of US$14.00 per share, or (ii) settle outstanding options and restricted share units in accordance with the terms of the Merger Agreement, and (b) the estimated transaction costs associated with the transactions contemplated by the Merger Agreement (the “Transactions”).

The Transactions contemplated by the Merger Agreement will be funded through (i) cash contributions contemplated by the equity commitment letters, each dated as of August 10, 2023 (the “Equity Commitment Letters”), by and between Parent and each of GA and Dragoneer, or their respective affiliates; and (ii) the rollover equity contribution from GA, Dragoneer, the Founders and certain other shareholders of the Company into Parent, as contemplated by the Rollover and Support Agreement.

Under the terms and subject to the conditions of the Equity Commitment Letter by GA (the “GA Equity Commitment Letter”), at the Closing, GA will provide, or cause to be provided, equity financing to Parent in an amount of US$316,390,606. The information disclosed in this paragraph is qualified in its entirety by reference to the GA Equity Commitment Letter, a copy of which is filed as Exhibit 7, and which is incorporated herein by reference.

Concurrently with the execution of the Merger Agreement, the members of the Consortium and the other shareholders who agreed to roll over their common shares into the Surviving Company (collectively, the “Supporting Shareholders”) and the beneficial owners listed therein entered into a rollover and support agreement dated as of August 10, 2023 (the “Rollover and Support Agreement”) with Parent, pursuant to which they have agreed with Parent, among other things, that they will vote all common shares owned directly or indirectly by them in favor of the authorization and approval of the Merger Agreement and the Transactions, including the Merger (and against any alternative transaction). In addition, each Supporting Shareholder agreed that (i) the Class A common shares and Class B common shares held by him, her or it will be contributed to Parent immediately prior to the Effective Time, and (ii) in consideration for such contribution, Parent will issue to each Supporting Shareholder Class A common shares and Class B common shares, respectively, in Parent. The information in this paragraph is qualified in its entirety by reference to the Rollover and Support Agreement, a copy of which is filed as Exhibit 8, and which is incorporated herein by reference.

Concurrently with the execution of the Merger Agreement, each member of the Consortium (or its applicable affiliate) entered into an interim investors agreement (the “Interim Investors Agreement”) with Parent, Merger Sub, and the other Supporting Shareholders pursuant to which the parties thereto agreed to certain terms and conditions that will govern the actions of Parent and Merger Sub and the relationship among the Supporting Shareholders with respect to the Transactions. The information disclosed in this paragraph is qualified in its entirety by reference to the Interim Investors Agreement, a copy of which is filed as Exhibit 9, and which is incorporated herein by reference.

Except as set forth in this Item 4 or Item 6 below, the Reporting Persons have no present plans or proposals that relate to, or that would result in, any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D of the Exchange Act.

Item 5. Interest in Securities of the Issuer.

Item 5 is hereby amended and supplemented with the following:

(a) The percentages used herein are calculated based upon on an aggregate of 40,663,392, the sum of (i) 38,939,254 Class A Common Shares outstanding (based on information provided by the Company as of August 8, 2023) and (ii) 1,724,138 Class A common shares that would result if all convertible notes of the Company held by

the Reporting Persons were converted into Class A common shares at the initial conversion price of US$29 per share.

By virtue of entering into the Rollover and Support Agreement and the Interim Investors Agreement, the Reporting Persons, Dragoneer and the Founders may be deemed to be members of a “group” with the other Supporting Shareholders pursuant to Section 13(d) of the Exchange Act. However, each Reporting Person expressly disclaims beneficial ownership of the common shares beneficially owned by any other reporting person(s), Dragoneer, the Founders or the other Supporting Shareholders. Neither the filing of this Statement nor any of its contents shall be deemed to constitute an admission that any of the Reporting Persons beneficially owns any Class A common shares or Class B common shares of the Company that are beneficially owned by any other reporting person(s), Dragoneer, the Founders or the other Supporting Shareholders. The Reporting Persons are only responsible for the information contained in this Statement and assume no responsibility for information contained in any other Schedules 13D filed by any other reporting person(s), Dragoneer, the Founders or the other Supporting Shareholders.

Accordingly, in the aggregate, the Reporting Persons, Dragoneer, the Founders and the other Supporting Shareholders may be deemed to beneficially own 46,282,969 Class A common shares, comprised of an aggregate of 13,709,703 Class A common shares, 5,172,418 Class A common shares issuable on conversion of the 2028 Convertible Notes and 27,400,848 Class A common shares issuable on conversion of Class B common shares, which, as calculated in accordance with Rule 13d-3(d)(1)(i), represents approximately 64.7% of the total number of Class A common shares based on (i) 38,939,254 Class A Common Shares outstanding (based on information provided by the Company as of August 8, 2023) and (ii) an aggregate of 32,573,266 Class A common shares issuable on conversion of all the 2028 Convertible Notes and all the Class B common shares.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to the Issuer.

Item 6 is hereby amended and supplemented as follows:

The information disclosed under Items 3 and 4 above is hereby incorporated by reference into this Item 6.

Except as described above or elsewhere in this Statement or incorporated by reference in this Statement, there are no contracts, arrangements, understandings or relationships (legal or otherwise) between the Reporting Persons or, to the best of their knowledge, any of the persons named in Schedule A hereto and any other person with respect to any securities of the Company, including, but not limited to, transfer or voting of any securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or losses, or the giving or withholding of proxies.

Item 7. Materials to Be Filed as Exhibits.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated as of August 14, 2023

SCHEDULE A

Members of the Management Committee (as of the date hereof)