UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 7)

MARCUS & MILLICHAP, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

566324109

(CUSIP Number)

Alexander Yarmolinsky

Chief Financial Officer

Phoenix Investments Holdings LLC

777 S. California Avenue

Palo Alto, CA 94304

(650) 494-1400

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

March 15, 2018

(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 §§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 §240.13d-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

SCHEDULE 13D

Explanatory Note

This Amendment No. 7 to the statement on Schedule 13D (“Amendment No. 7”) relates to the common stock, par value $0.0001 per share, of Marcus & Millichap, Inc.

George M. Marcus, Ionian Investments Manager LLC, and Phoenix Investments Holdings LLC filed the initial statement on Schedule 13D on November 12, 2013 (the “Initial Statement”) and capitalized terms used in this Amendment No. 7, but not otherwise defined, have the meanings given to them in the Initial Statement. This Amendment No. 7 amends and supplements the disclosures under Items 4 and 6 and amends and restates the disclosures in the cover pages hereto and Items 5 and 7 of Amendment No. 6 to the Initial Statement filed on November 29, 2017 (“Amendment No. 6”).

Item 4. Purpose of Transaction.

Item 4 of Amendment No. 6 is hereby amended and supplemented by deleting the disclosure under paragraph (j) and adding the following in its place:

“Except as described in this Item 4, Item 6 and potential pro rata distributions to Phoenix’s members, the Reporting Persons do not have, as of the date of this Amendment No. 7, any other plans or proposals that relate to or would result in any of the actions or events specified in clauses (a) through (i) of Item 4 of Schedule 13D. The Reporting Persons may change their plans or proposals in the future. In determining from time to time whether to sell or to distribute to Phoenix’s members the MMI Common Stock reported as beneficially owned in this Schedule 13D, as amended, (and in what amounts) or to retain such securities, the Reporting Persons will take into consideration such factors as they deem relevant, including the business and prospects of the Issuer, anticipated future developments concerning the Issuer, existing and anticipated market conditions from time to time, general economic conditions, regulatory matters, and other opportunities available to the Reporting Persons. The Reporting Persons reserve the right to acquire additional securities of the Issuer in the open market, in privately negotiated transactions (which may be with the Issuer or with third parties), or otherwise; to dispose of all or a portion of their holdings of securities of the Issuer; or to change their intention with respect to any or all of the matters referred to in this Item 4.”

Item 5. Interest in Securities of the Issuer.

Item 5 of Amendment No. 6 is hereby amended and restated by the following:

“(a) Based on the Issuer’s Form 10-K filed on March 16, 2018, 38,578,808 shares of MMI Common Stock were outstanding as of March 5, 2018. As of March 22, 2018, the Reporting Persons beneficially own the following amounts of MMI Common Stock:

Mr. Marcus’ beneficial ownership consists of:

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The Reporting Persons have the sole power to dispose or direct the disposition of the following amounts of MMI Common Stock:

The Reporting Persons have the shared power to vote or direct the vote of the following amounts of MMI Common Stock:

As noted above, Mr. Marcus’ shared power to vote or direct the vote consist of (i) 290,259 shares held directly by the George and Judy Marcus Foundation II of which Mr. Marcus, as trustee, may direct the vote, and (ii) 18,068,934 shares held directly by Phoenix of which Mr. Marcus, as the sole member and manager of Ionian, may direct the vote. Ionian, as the sole non-member manager of Phoenix, shares with Phoenix the power to vote the 18,068,934 shares held directly by Phoenix.

The Reporting Persons have shared power to dispose or direct the disposition of the following amounts of MMI Common Stock:

As noted above, Mr. Marcus’ shared power to dispose or direct the disposition consists of (i) 290,259 shares held directly by the George and Judy Marcus Foundation II of which Mr. Marcus, as trustee, may direct the disposition, and (ii) 18,068,934 shares held directly by Phoenix of which Mr. Marcus, as the sole member and manager of Ionian, may direct the disposition. Ionian, as the sole non-member manager of Phoenix, shares with Phoenix the power to dispose the 18,068,934 shares held directly by Phoenix.

On March 13, 2018, Phoenix sold 47,639 shares of MMI Common Stock at an average price of $36.1338 per share pursuant to Rule 144 of the Securities Act.

On March 14, 2018, Phoenix sold 69,599 shares of MMI Common Stock at an average price of $36.0244 per share pursuant to Rule 144 of the Securities Act.

On March 15, 2018, Phoenix sold 101,208 shares of MMI Common Stock at an average price of $35.9844 per share pursuant to Rule 144 of the Securities Act.

On March 16, 2018, Phoenix sold 67,609 shares of MMI Common Stock at an average price of $35.8109 per share pursuant to Rule 144 of the Securities Act.

On March 19, 2018, Phoenix sold 50,000 shares of MMI Common Stock at an average price of $35.5113 per share pursuant to Rule 144 of the Securities Act.

On March 20, 2018, Phoenix sold 81,401 shares of MMI Common Stock at an average price of $35.7248 per share pursuant to Rule 144 of the Securities Act.

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On March 21, 2018, Phoenix sold 28,015 shares of MMI Common Stock at an average price of $35.8774 per share pursuant to Rule 144 of the Securities Act.

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

Item 6 of the Initial Statement is hereby amended and supplemented as follows:

On March 21, 2018, Phoenix entered into a trading plan (the “Trading Plan”) with Raymond James & Associates, Inc. (“Raymond James”) pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. Under the Trading Plan, Raymond James may make periodic sales of up to an aggregate of 402,872 shares of Common Stock on behalf of Phoenix up to the earlier of the date on which all shares are sold or December 31, 2018, subject to the terms of the Trading Plan. Phoenix makes no commitment in terms of the timing or amount of such transactions, if any, which will depend on market conditions, including the price of the Common Stock, as well as other factors.

Item 7. Material to be filed as Exhibits.

Item 7 of Amendment No. 6 is hereby amended and restated by the following:

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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: March 23, 2018

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EXHIBIT A

JOINT FILING AGREEMENT

Each of the undersigned hereby agrees that the Schedule 13D, to which this Agreement is attached as Exhibit A, and all amendments thereto may be filed on behalf of each such person.

Dated: March 23, 2018

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