UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q/A

(Mark One)

For the quarterly period ended June 30, 2011

or

For the transition period from _________ to ______.

Commission File Number 001-10932

WisdomTree Investments, Inc.

(Exact name of registrant as specified in its charter)

212-801-2080

(Registrant’s Telephone Number, Including Area Code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act’) during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  ¨    No  x

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    x  Yes    ¨  No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of September 1, 2011 there were 115,730,107 shares of the registrant’s Common Stock, $.01 par value per share, outstanding (voting securities).

WisdomTree Investments, Inc.

Explanatory Note

The purpose of this Amendment No. 1 on Form 10-Q/A to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2011 of WisdomTree Investments, Inc. filed with the Securities and Exchange Commission on September 7, 2011 (the “Form 10-Q”) is solely to furnish the Interactive Data File as Exhibit 101 to the Form 10-Q in accordance with Rule 405 of regulation S-T.

No other changes have been made to the Form 10-Q. This Amendment No. 1 continues to speak as of the original filing date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date and does not modify or update in way disclosures made in the original Form 10-Q.

Pursuant to Rule 406T, the interactive data files in Exhibit 1010 hereto are deemed not filed or a part of a registration statement or prospectus for purposes of Section 11 or 12 of the Securities Act of 1933, as amended, are deemed not filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended ,and otherwise is not subject to liability under these sections and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such filing.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned thereunto duly authorized on this 30^th day of September, 2011.

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