SUMMARY

This summary highlights selected information from this proxy statement/prospectus. It may not contain all of the information that is important to you. You are urged to read carefully the entire proxy statement/prospectus and the other documents referred to in this proxy statement/prospectus in order to fully understand the merger agreement and the proposed merger. See “Where You Can Find More Information” beginning on page 155 of this proxy statement/prospectus. Each item in this summary refers to the page of this proxy statement/prospectus on which that subject is discussed in more detail.

Information about MSCI, RiskMetrics and Crossway Inc. (See Page 52)

MSCI Inc.

MSCI Inc., which is referred to in this proxy statement/prospectus as MSCI, was incorporated in the State of Delaware in 1998 and became a public company in November 2007. MSCI is a leading global provider of investment decision support tools, including indices and portfolio risk and performance analytics for use by institutions in managing equity, fixed income and multi-asset class portfolios. MSCI’s principal products are global equity indices marketed under the MSCI brand and equity portfolio analytics marketed under the Barra brand. MSCI’s products are used in many areas of the investment process, including portfolio construction and optimization, performance benchmarking and attribution, risk management and analysis, index-linked investment product creation, asset allocation, investment manager selection and investment research. MSCI operates 21 offices in 15 countries and has over 3,100 clients across 67 countries, to which it primarily licenses annual, recurring subscriptions for the use of its products.

The principal trading market for MSCI’s common stock (NYSE: MXB) is the New York Stock Exchange. The principal executive offices of MSCI are located at 88 Pine Street, New York, NY 10005; its telephone number is (212) 804-3900; and its website is www.mscibarra.com.

RiskMetrics Group, Inc.

RiskMetrics Group, Inc., which is referred to in this proxy statement/prospectus as RiskMetrics, was incorporated in the State of Delaware in 1998 and became a public company in January 2008. RiskMetrics is a leading provider of risk management and corporate governance products and services to participants in the global financial markets. RiskMetrics products enable clients to better understand and manage the risks associated with their financial holdings, to provide greater transparency to their internal and external constituencies, to satisfy regulatory and reporting requirements and to make more informed investment decisions. RiskMetrics consists of two industry leading businesses: risk management and corporate governance. The risk management segment provides multi-asset, position based risk and wealth management products and services to clients in the global financial markets through comprehensive, interactive products and services that allow clients to measure and quantify portfolio risk across security types, geographies and markets. The corporate governance business is represented by Institutional Shareholder Services, which is referred to as ISS in this proxy statement/prospectus, which provides corporate governance and specialized financial research and analysis services to institutional investors and corporations around the world to assist them with their proxy voting responsibilities. RiskMetrics serves a global client base through a network of 20 offices in 12 countries and has approximately 3,500 clients located in 53 countries, to which it sells its products primarily on an annual subscription basis, generally receiving upfront subscription payments.

The principal trading market for RiskMetrics’ common stock (NYSE: RISK) is the New York Stock Exchange. The principal executive offices of RiskMetrics are located at 1 Chase Manhattan Plaza, 44^th Floor, New York, NY 10005; its telephone number is (212) 981-7475; and its website is www.riskmetrics.com.

Crossway Inc.

Crossway Inc., which is referred to in this proxy statement/prospectus as Merger Sub, is a Delaware corporation and a wholly owned subsidiary of MSCI. Merger Sub was formed solely for the purpose of consummating a merger with RiskMetrics. Merger Sub has not carried on any activities to date, except for activities incidental to its formation and activities undertaken in connection with the merger.

The principal executive offices of Merger Sub are located at 88 Pine Street, New York, NY 10005 and its telephone number is (212) 804-3900.

The Merger (See Page 59).

MSCI, Merger Sub and RiskMetrics have entered into the Agreement and Plan of Merger, dated as of February 28, 2010, which, as it may be amended from time to time, is referred to in this proxy statement/prospectus as the merger agreement. Subject to the terms and conditions of the merger agreement and in accordance with Delaware law, Merger Sub will be merged with and into RiskMetrics, with RiskMetrics continuing as the surviving corporation. Upon completion of this transaction, which is referred to in this proxy statement/prospectus as the merger, RiskMetrics will be a wholly owned subsidiary of MSCI, and RiskMetrics common stock will no longer be outstanding or publicly traded.

A copy of the merger agreement is attached as Annex A to this proxy statement/prospectus. You should read the merger agreement carefully because it is the legal document that governs the merger.

Special Meeting of RiskMetrics’ Stockholders (See Page 53).

Meeting. The special meeting will be held at One Chase Manhattan Plaza, 44th Floor, New York, NY 10005 on May 27, 2010 at 10:00 a.m., local time. At the special meeting, RiskMetrics stockholders will be asked to vote on the following proposals:

Record Date. Only RiskMetrics stockholders of record at the close of business on April 26, 2010 will be entitled to receive notice of and to vote at the special meeting or any adjournment of the special meeting. As of the close of business on the record date of April 26, 2010, there were 69,104,540 shares of RiskMetrics common stock outstanding and entitled to vote at the special meeting. Each holder of RiskMetrics common stock is entitled to one vote for each share of RiskMetrics common stock owned as of the record date.

Required Vote. To adopt the merger agreement, holders of a majority of the shares of RiskMetrics common stock outstanding and entitled to vote on the proposal must vote in favor of adoption of the merger agreement. RiskMetrics cannot complete the merger unless its stockholders adopt the merger agreement. Because approval is based on the affirmative vote of a majority of the outstanding shares of RiskMetrics common stock entitled to vote thereon, a RiskMetrics stockholder’s failure to vote, an abstention from voting or the failure of a RiskMetrics stockholder who holds his or her shares in “street name” through a broker or other nominee to give voting instructions to such broker or other nominee will have the same effect as a vote “AGAINST” adoption of the merger agreement.

To approve the adjournment of the special meeting, if necessary to solicit additional proxies if there are not sufficient votes to adopt the merger agreement at the time of the special meeting, the affirmative vote of holders of a majority of the votes cast at the special meeting is required, if a quorum is present. If a quorum is not present, a majority of the outstanding RiskMetrics voting interests present at the special meeting may adjourn the

meeting until a quorum is present. Abstentions and broker non-votes will have no effect on the outcome of the vote to adjourn the special meeting if a quorum is present and will have the same effect as a vote “AGAINST” the proposal to adjourn the special meeting if a quorum is not present. Shares not in attendance at the special meeting will have no effect on the outcome of any vote to adjourn the special meeting.

See “—Voting Agreement” below for information regarding RiskMetrics stockholders who have committed to vote shares of RiskMetrics common stock in favor of the two proposals described above.

Stock Ownership of and Voting by RiskMetrics’ Directors and Executive Officers. At the close of business on the record date for the special meeting, RiskMetrics’ directors and executive officers and their affiliates beneficially owned and had the right to vote 28,438,956 shares of RiskMetrics common stock at the special meeting, which represents approximately 41.2% of the shares of RiskMetrics common stock entitled to vote at the special meeting.

It is expected that RiskMetrics’ directors and executive officers will vote their shares “FOR” the adoption of the merger agreement, although, except for Ethan Berman, the chief executive officer of RiskMetrics, none of them has entered into any agreement requiring them to do so.

What RiskMetrics’ Stockholders Will Receive in the Merger (See Page 103).

If the merger is completed, RiskMetrics’ stockholders will be entitled to receive in the merger, for each share of RiskMetrics common stock that they own, a combination of $16.35 in cash, without interest, and 0.1802 of a share of MSCI Class A common stock, which together with cash payable in lieu of any fractional shares as described below are collectively referred to in this proxy statement/prospectus as the merger consideration.

MSCI will not issue any fractional shares of its Class A common stock in the merger. Instead, the total number of shares of MSCI Class A common stock that each RiskMetrics stockholder will receive in the merger will be rounded down to the nearest whole number, and each RiskMetrics stockholder will receive cash, without interest, for any fractional shares of MSCI Class A common stock that he or she would otherwise receive in the merger. The amount of cash for fractional shares will be calculated by multiplying the fraction of a share of MSCI Class A common stock that the RiskMetrics stockholder would otherwise be entitled to receive in the merger by the average of the closing prices for a share of MSCI Class A common stock on the New York Stock Exchange for the 20 trading days ending on the third trading day immediately preceding the completion of the merger.

Example: If you currently own 100 shares of RiskMetrics common stock, you will be entitled to receive $1,635.00 in cash, without interest, and 18 shares of MSCI Class A common stock. In addition, you will be entitled to receive cash for the market value of 0.02 shares of MSCI Class A common stock at the average of the closing prices for a share of MSCI Class A common stock on the New York Stock Exchange for the 20 trading days ending on the third trading day immediately preceding the completion of the merger.

The ratio of 0.1802 of a share of MSCI Class A common stock for each share of RiskMetrics common stock (which is referred to in this proxy statement/prospectus as the exchange ratio) is fixed, which means that it will not change between now and the date of the merger, regardless of whether the market price of either MSCI or RiskMetrics common stock changes. Therefore, the value of the stock portion of the merger consideration will depend on the market price of MSCI Class A common stock at the time RiskMetrics’ stockholders receive MSCI Class A common stock in the merger. The market price of MSCI Class A common stock will fluctuate prior to the merger, and the market price of MSCI Class A common stock when received by RiskMetrics’ stockholders after the merger is completed could be greater, less than or the same as the current market price of MSCI Class A common stock or the market price at the time of the special meeting.

Treatment of Equity Awards (See Page 104).

Upon completion of the merger, RiskMetrics options will be converted into options to purchase MSCI Class A common stock. MSCI and RiskMetrics agreed that, subject to the requirements of Section 409A of the Internal Revenue Code of 1986, as amended from time to time, which is referred to in this proxy statement/prospectus as the Code, the following mechanism will be used to convert each RiskMetrics option outstanding immediately prior to the completion of the merger into an adjusted option to acquire shares of MSCI Class A common stock, on the same terms and conditions as were applicable under the RiskMetrics option immediately prior to the completion of the merger. The number of shares of MSCI Class A common stock subject to the adjusted option will be equal to the product of (i) the number of shares of RiskMetrics common stock subject to the RiskMetrics option immediately prior to the completion of the merger multiplied by (ii) the option exchange ratio (as described below), rounded down to the nearest whole share. The exercise price per share of MSCI Class A common stock subject to an adjusted option will be an amount (rounded up to the nearest whole cent) equal to the quotient of (A) the exercise price per share of RiskMetrics common stock subject to the RiskMetrics option immediately prior to the completion of the merger divided by (B) the option exchange ratio. The option exchange ratio will be equal to or less than the quotient of (a) the value of the merger consideration based on the closing price of a share of MSCI Class A common stock on the New York Stock Exchange on February 24, 2010 divided by (b) the closing price of a share of MSCI Class A common stock on February 24, 2010. If the closing price of a share of MSCI Class A common stock on the trading date immediately prior to the completion of the merger is $29.96 (the closing price of a share of MSCI Class A common stock on the New York Stock Exchange on February 24, 2010) or lower, the option exchange ratio will be 0.7260. In order to comply with Section 409A of the Code, if the closing price of a share of MSCI Class A common stock on the trading date immediately prior to the completion of the merger is greater than $29.96, the option exchange ratio will be lower than 0.7260, and will be equal to the quotient of (a) the closing price of a share of RiskMetrics common stock on the trading date immediately prior to the completion of the merger divided by (b) the closing price of a share of MSCI Class A common stock on the trading date immediately prior to the completion of the merger.

At the completion of the merger, each restricted stock award (which represents a share of RiskMetrics common stock subject to vesting and forfeiture restrictions) outstanding at the completion of the merger, will be converted into a restricted stock award relating to a number of shares of MSCI Class A common stock equal to the product of (i) the number of shares of RiskMetrics common stock subject to the RiskMetrics restricted stock award immediately prior to the completion of the merger multiplied by (ii) 0.7260, rounded to the nearest whole share (with 0.50 being rounded upward). Each converted restricted stock award will remain subject to the same vesting and forfeiture terms as were applicable to the RiskMetrics restricted stock award prior to the completion of the merger.

Recommendation of the RiskMetrics Board of Directors (See Page 71).

RiskMetrics’ board of directors unanimously determined that the merger agreement and the transactions contemplated thereby are advisable, in the best interests of RiskMetrics and its stockholders and unanimously approved the merger agreement and the transactions contemplated thereby. The RiskMetrics board of directors unanimously recommends that RiskMetrics’ stockholders vote “FOR” adoption of the merger agreement. For the factors considered by the RiskMetrics board of directors in reaching its decision to approve the merger agreement, see “The Merger—RiskMetrics’ Reasons for the Merger; Recommendation of RiskMetrics’ Board of Directors” beginning on page 71 of this proxy statement/prospectus.

In addition, the RiskMetrics board of directors recommends that RiskMetrics’ stockholders vote “FOR” the RiskMetrics proposal to adjourn the special meeting, if necessary to solicit additional proxies if there are not sufficient votes to adopt the merger agreement at the time of the special meeting.

Opinion of RiskMetrics’ Financial Advisor (See Page 78).

The RiskMetrics board of directors received an opinion, dated February 28, 2010, from Evercore Group L.L.C., referred to in this proxy statement/prospectus as Evercore, that, as of that date and based on and subject to assumptions made, matters considered and limitations on the scope of review undertaken by Evercore as set forth therein, the merger consideration was fair, from a financial point of view, to the holders of the shares of RiskMetrics common stock entitled to receive such consideration. The full text of Evercore’s written opinion, which sets forth, among other things, the procedures followed, assumptions made, matters considered and limitations on the scope of review undertaken by Evercore in rendering its opinion is attached as Annex C to this proxy statement/prospectus. The opinion was directed to the RiskMetrics board of directors and addresses only the fairness, from a financial point of view, of the merger consideration to the holders of shares of RiskMetrics common stock entitled to receive such consideration. The opinion does not address any other aspect of the proposed merger and does not constitute a recommendation to the RiskMetrics board of directors or to any other persons in respect of the proposed merger, including as to how any holder of shares of RiskMetrics common stock should vote or act in respect of the proposed merger.

Ownership of MSCI After the Merger (See Page 59).

Based on the number of shares of RiskMetrics common stock (including RiskMetrics restricted stock awards) outstanding as of April 26, 2010, MSCI expects to issue approximately 12,573,706 shares of its Class A common stock (including approximately 161,039 restricted shares) to RiskMetrics’ stockholders pursuant to the merger and reserve for issuance approximately 4,288,187 additional shares of MSCI Class A common stock in connection with the conversion of RiskMetrics’ outstanding options assuming all RiskMetrics options and restricted stock awards outstanding as of such date are converted into MSCI options and restricted stock awards at an exchange ratio calculated as though such date were the closing date of the merger. The actual number of shares of MSCI Class A common stock to be issued and reserved for issuance pursuant to the merger will be determined at the completion of the merger based on the exchange ratio of 0.1802, the applicable option exchange ratio and the number of shares of RiskMetrics common stock (including RiskMetrics restricted stock awards) and RiskMetrics options outstanding at such time. Immediately after completion of the merger, it is expected that former RiskMetrics’ stockholders will own approximately 13.4% of the outstanding MSCI Class A common stock, based on the number of shares of RiskMetrics and MSCI Class A common stock outstanding, on a fully diluted basis, as of April 26, 2010 and the assumptions described above.

MSCI Stockholder Approval Is Not Required.

MSCI stockholders are not required to adopt the merger agreement or approve the merger or the issuance of the shares of MSCI Class A common stock in connection with the merger.

Interests of Certain Persons in the Merger (See Page 130).

In considering the recommendation of the RiskMetrics board of directors with respect to the merger agreement, stockholders should be aware that RiskMetrics’ directors and executive officers have interests in the merger that may be different from, or in addition to, RiskMetrics’ stockholders generally. The RiskMetrics board of directors was aware of and considered these interests, among other matters, in evaluating and negotiating the merger agreement and in recommending to the stockholders that the merger agreement be approved.

These interests and arrangements include:

Listing of MSCI Stock and Delisting and Deregistration of RiskMetrics Stock (See Page 105).

MSCI will apply to have the shares of its Class A common stock to be issued in the merger approved for listing on the New York Stock Exchange, where MSCI Class A common stock is currently traded. If the merger is completed, RiskMetrics shares will no longer be listed on the New York Stock Exchange, and will be deregistered under the Securities Exchange Act of 1934, as amended, which is referred to in this proxy statement/prospectus as the Exchange Act.

Appraisal Rights Available (See Page 93).

Under Delaware law, if the merger is completed, record holders of RiskMetrics common stock who do not vote in favor of the adoption of the merger agreement and who otherwise properly assert their appraisal rights will be entitled to seek appraisal for, and obtain payment in cash for the judicially determined fair value of, their shares of RiskMetrics common stock, in lieu of receiving the merger consideration. This value could be more than, the same as, or less than the value of the merger consideration. The relevant provisions of the General

Corporation Law of the State of Delaware are included as Annex D to this proxy statement/prospectus. You are encouraged to read these provisions carefully and in their entirety. Moreover, due to the complexity of the procedures for exercising the right to seek appraisal, RiskMetrics’ stockholders who are considering exercising such rights are encouraged to seek the advice of legal counsel. Failure to strictly comply with these provisions will result in loss of the right of appraisal.

Completion of the Merger Is Subject to Certain Conditions (See Page 106).

The obligation of each of MSCI, RiskMetrics and Merger Sub to complete the merger is subject to the satisfaction (or, to the extent permitted by applicable law, waiver) of a number of conditions, including the following:

In addition, the obligations of MSCI and Merger Sub to complete the merger are subject to the satisfaction (or, to the extent permitted by applicable law, waiver) of the following conditions:

MSCI and RiskMetrics cannot be certain when, or if, the conditions to the merger will be satisfied or waived, or that the merger will be completed.

The Merger May Not Be Completed Without All Required Regulatory Approvals (See Page 91).

Completion of the merger is conditioned upon the receipt of certain governmental clearances or approvals, including, but not limited to, the expiration or termination of the applicable waiting period relating to the merger under the HSR Act and the expiration or termination of the applicable waiting period, or receipt of approval, under each foreign antitrust law that relates to the merger. MSCI and RiskMetrics each filed its required HSR notification and report form with respect to the merger on March 16, 2010. On April 12, 2010, MSCI voluntarily withdrew its notification and report form and refiled it on April 14, 2010 in order to allow more time for the staff of the Antitrust Division of the Department of Justice to review the proposed merger. As a result of the refiling, the waiting period under the HSR Act will expire on May 14, 2010 unless it is extended by a request for additional information or terminated earlier. MSCI and RiskMetrics have agreed to use their reasonable best efforts to obtain all regulatory approvals required to complete the merger. However, in using their reasonable best efforts to obtain these required regulatory approvals, under the terms of the merger agreement, neither MSCI nor RiskMetrics is required to take certain actions (such as divesting or holding separate assets or entering into settlements or consent decrees with governmental authorities) with respect to any of the material businesses, assets or properties of MSCI or RiskMetrics or any of their respective material subsidiaries (except that, if requested by MSCI, RiskMetrics will use reasonable best efforts to take any such action reasonably necessary to obtain regulatory clearance, but only to the extent that such action is conditioned on the completion of the merger and does not reduce the amount or delay the payment of the merger consideration). A business of MSCI or RiskMetrics or any of their respective subsidiaries generating revenues in calendar year 2009 that are in excess of 5% of the aggregate revenues generated by MSCI and its subsidiaries, taken as a whole, in calendar year 2009, is considered a “material business” for these purposes.

Financing (See Page 127).

On February 28, 2010, MSCI entered into a debt commitment letter with Morgan Stanley Senior Funding, Inc., referred to in this proxy statement/prospectus as MSSF, pursuant to which MSSF has committed to provide senior secured credit facilities in an aggregate amount of $1,375 million to finance the merger, replace MSCI’s and RiskMetrics’ existing credit facilities and provide ongoing working capital and liquidity to MSCI. On March 23, 2010, MSCI and MSSF entered into supplemental commitment letters with each of Credit Suisse AG, Cayman Islands Branch and Bank of America, N.A., referred to in this proxy statement/prospectus as CS and BofA, respectively, pursuant to which (i) CS and BofA each committed to provide $137.5 million of the senior secured credit facilities (subject to pro rata reduction if the aggregate commitments in respect of the term loan facility portion of the senior secured credit facilities are reduced pursuant to the terms of the debt commitment letter), and (ii) the commitments of MSSF were reduced by the aggregate commitments provided by CS and BofA. For a more complete description of MSCI’s debt financing for the merger, see the section entitled “Description of Debt Financing” beginning on page 127 of the proxy statement/prospectus.

The Merger Is Expected to Occur in MSCI’s Third Fiscal Quarter of 2010 (See Page 103).

The merger will occur within five business days after the conditions to its completion have been satisfied or, to the extent permissible, waived, unless otherwise mutually agreed upon by the parties. As of the date of this proxy

statement/prospectus, the merger is expected to occur in MSCI’s third fiscal quarter of 2010 (which is the quarterly period ending August 31, 2010). However, there can be no assurance as to when, or if, the merger will occur.

No Solicitation by RiskMetrics (See Page 111).

Neither RiskMetrics nor any of its subsidiaries will, nor will RiskMetrics or any of its subsidiaries authorize or permit any of its or their officers, directors, employees or representatives to, (i) solicit, initiate or take any action to knowingly facilitate or encourage the submission of any competing acquisition proposal from any third party relating to an acquisition of RiskMetrics, (ii) enter into or participate in any discussions or negotiations regarding any such proposal or furnish any nonpublic information relating to RiskMetrics or its subsidiaries to such third party, (iii) fail to make, withdraw or modify in a manner adverse to MSCI the recommendation of the RiskMetrics board of directors in favor of the adoption of the merger agreement, (iv) grant any waiver or release under any standstill or similar agreement or (v) enter into an agreement relating to a competing acquisition proposal. Notwithstanding these restrictions, however, the merger agreement provides that, under specified circumstances at any time prior to the adoption of the merger agreement by RiskMetrics’ stockholders:

Unless the action is required by applicable law or court order, the actions described in the preceding two bullets may be taken only if the RiskMetrics board of directors determines in good faith that such action is required by its fiduciary duties to RiskMetrics’ stockholders under Delaware law.

MSCI has the right to terminate the merger agreement if, prior to the special meeting, the RiskMetrics board of directors changes its recommendation in favor of the adoption of the merger agreement in a manner adverse to MSCI. In addition, the board of directors of RiskMetrics may, in response to a competing acquisition proposal and after complying with the notice and other conditions specified in the merger agreement, terminate the merger agreement to enter into a definitive agreement with respect to the superior acquisition proposal and upon such termination, RiskMetrics’ obligation to call and hold a stockholders’ meeting to vote on the merger would cease. See “The Merger Agreement—Termination of the Merger Agreement” beginning on page 119 of this proxy statement/prospectus. RiskMetrics, however, does not have the right to terminate the merger agreement if the RiskMetrics board of

directors changes its recommendation in response to any event other than a superior acquisition proposal; in such case, unless MSCI terminates the merger agreement, RiskMetrics would remain obligated to call and hold a special meeting of its stockholders for purposes of voting on a proposal to adopt the merger agreement.

The Voting Agreement (See Page 124).

To induce MSCI to enter into the merger agreement, various RiskMetrics’ stockholders, including Ethan Berman, the chief executive officer of RiskMetrics, entered into a voting and irrevocable proxy agreement with MSCI concurrently with the merger agreement, which, as amended by amendment no. 1 to the voting agreement, is referred to in this proxy statement/prospectus as the voting agreement. As of the record date (April 26, 2010), 34,664,426 shares of RiskMetrics common stock are subject to the voting agreement, or approximately 50.2% of the outstanding shares of RiskMetrics common stock as of April 26, 2010. Except as described in the following sentence, these stockholders have agreed to vote all of their shares of RiskMetrics common stock in favor of, among other things, the adoption of the merger agreement and any adjournment of the special meeting if necessary to solicit additional proxies if there are not sufficient votes to adopt the merger agreement at the time of the special meeting, and against, among other things, any alternative business combination involving RiskMetrics. The voting agreement, however, provides that if the RiskMetrics board of directors changes its recommendation with respect to the merger, only a total of 13,770,525 shares, or approximately 19.9% of the outstanding shares of RiskMetrics common stock as of April 26, 2010 will be required to be voted in the manner described above in favor of the merger, with each stockholder’s remaining shares voted in a manner deemed appropriate by such stockholder in its or his sole discretion. In addition, if the RiskMetrics board of directors changes its recommendation in response to a superior acquisition proposal, the RiskMetrics board of directors may terminate the merger agreement (after complying with the notice and other conditions specified in the merger agreement), which would result in the concurrent termination of the voting agreement as described below.

The voting agreement will terminate on the earliest of (i) the adoption of the merger agreement by RiskMetrics’ stockholders at the special meeting called for purposes of voting on the merger agreement, (ii) provided that the special meeting has concluded, the failure of RiskMetrics’ stockholders to approve the merger agreement at that meeting, (iii) November 28, 2010 and (iv) the termination of the merger agreement in accordance with its terms or any amendment to the merger agreement that reduces the per share merger consideration, that changes the kind or form of, or cash/equity per share allocation of, the consideration to be received (other than by adding cash consideration) or that amends the termination provisions of the merger agreement.

Accordingly, as long as the voting agreement remains in effect and the RiskMetrics board of directors does not change its recommendation, the adoption of the merger agreement by RiskMetrics’ stockholders is assured.

Termination of the Merger Agreement (See Page 119).

The merger agreement may be terminated at any time before the completion of the merger by mutual written consent of MSCI and RiskMetrics.

The merger agreement may also be terminated by either MSCI or RiskMetrics prior to the completion of the merger if:

The merger agreement may also be terminated by MSCI prior to the completion of the merger if:

The merger agreement may also be terminated prior to the completion of the merger by RiskMetrics if the RiskMetrics board of directors authorizes RiskMetrics, in response to a competing acquisition proposal and after complying with the notice and other conditions specified in the merger agreement, to enter into a definitive agreement with respect to the superior acquisition proposal.

Termination Fees (See Page 120).

RiskMetrics has agreed to pay a fee of $50 million to MSCI if the merger agreement is terminated under any of the following circumstances:

MSCI has agreed to pay a fee of $100 million to RiskMetrics if the merger agreement is terminated under any of the following circumstances:

MSCI has no obligation to pay the termination fee pursuant to the first bullet above if the failure of the condition to be satisfied is caused by RiskMetrics’ willful and intentional material breach of its obligations to cooperate with MSCI’s efforts to obtain the financing for the merger.

Subject to certain limited exceptions, if RiskMetrics or any of its subsidiaries, affiliates and representatives brings any suit or legal action (whether in law or in equity) against MSCI or any of its subsidiaries, affiliates and representatives (including financing sources) relating to the transactions contemplated by the merger agreement, RiskMetrics will cease to have the right to receive the termination fee from MSCI. See “The Merger Agreement—Specific Performance; Remedies—Termination of RiskMetrics’ Right to Receive MSCI Termination Fee Under Certain Circumstances” beginning on page 122 of this proxy statement/prospectus.

If either party pays the termination fee as described above, the termination fee will constitute the other party’s sole and exclusive remedy against the paying party.

RiskMetrics has also agreed to reimburse MSCI, in certain circumstances, for 100% of MSCI’s reasonable out-of-pocket fees and expenses up to $10 million, including if the merger agreement is terminated because RiskMetrics’ stockholders fail to adopt the merger agreement at the RiskMetrics’ stockholders’ meeting called for that purpose.

Specific Performance; Remedies (See Page 122).

Under the merger agreement, each of MSCI and RiskMetrics is entitled to seek an injunction or injunctions to prevent breaches of the merger agreement or to enforce specifically the terms and provisions of the merger agreement, in addition to any other remedy to which that party may be entitled to at law or in equity. However, under the merger agreement, no party or any of its subsidiaries, affiliates and representatives (including financing sources) will have any liability for monetary damages relating to the transactions contemplated by the merger agreement, except to the extent resulting from such party’s willful and intentional material breach.

Material U.S. Federal Income and Estate Tax Consequences (See Page 96).

In general, U.S. Holders (as defined under “The Merger—Material U.S. Federal Income and Estate Tax Consequences—Tax Consequences for U.S. Holders”) will recognize capital gain or loss for U.S. federal income tax purposes on the exchange of their RiskMetrics common stock for shares of MSCI Class A common stock and cash in an amount equal to the difference, if any, between (i) the sum of the fair market value of the MSCI Class A common stock on the date of the exchange and cash received (including cash received in lieu of a fractional share of MSCI Class A common stock) and (ii) the U.S. Holder’s adjusted tax basis in the RiskMetrics common stock surrendered in the exchange.

The U.S. federal income tax consequences described above may not apply to all holders of RiskMetrics common stock, including certain holders specifically referred to on pages 96 and 97 of this proxy statement/prospectus. Your tax consequences will depend on your own situation. You should consult your tax advisor to determine the particular tax consequences of the merger to you.

Accounting Treatment (See Page 99).

In accordance with accounting principles generally accepted in the United States, MSCI will account for the merger as an acquisition of a business.

Rights of RiskMetrics’ Stockholders Will Change as a Result of the Merger (See Page 141).

RiskMetrics’ stockholders will have different rights once they become MSCI stockholders due to differences between the organizational documents of MSCI and RiskMetrics. These differences are described in more detail under “Comparison of Stockholder Rights” beginning on page 141 of this proxy statement/prospectus.

Litigation Relating to the Merger (See Page 100).

On March 4, 2010, a putative stockholder class action complaint was filed against RiskMetrics, MSCI and the individual members of the RiskMetrics board of directors in the Court of Chancery of the State of Delaware challenging the proposed merger and seeking monetary damages, as well as declaratory, injunctive and other equitable relief. The complaint generally alleges, among other things, that the members of the RiskMetrics board of directors breached their fiduciary duties by approving the proposed merger; that RiskMetrics and MSCI aided and abetted such breaches of fiduciary duties; and that the consideration to be paid to the public stockholders of RiskMetrics pursuant to the merger agreement is inadequate. In addition, the complaint alleges that certain of the members of the RiskMetrics board of directors breached their fiduciary duties by agreeing to the voting agreement. The complaint seeks, among other things, damages and injunctive relief prohibiting the defendants from consummating the merger. On April 14, 2010, plaintiff filed an amended putative class action complaint against defendants, adding Merger Sub as a defendant. In addition to the claims asserted in the original complaint, the amended complaint generally alleges, among other things, that the disclosures contained in the preliminary proxy statement/prospectus filed on April 2, 2010 with the Securities and Exchange Commission were materially false, misleading and omissive. For example, the amended complaint challenges the disclosures concerning the methodologies used by Evercore in rendering its fairness opinion, RiskMetrics’s January 2010 financial forecasts, MSCI’s post-2010 financial forecasts, the negotiation of the voting agreement, RiskMetrics’ December 2009 strategic plan and certain strategic alternatives considered by the RiskMetrics board of directors.

On April 23, 2010, the parties to the action reached an agreement in principle to resolve and settle the action. The settlement is subject to documentation and customary conditions, including consummation of the merger, completion of certain confirmatory discovery, class certification and final approval by the Court of Chancery of the State of Delaware following notice to the stockholders of RiskMetrics. A hearing will be scheduled at which the Court of Chancery will consider the fairness, reasonableness and adequacy of the settlement. The settlement will not affect the form or amount of the consideration to be received by RiskMetrics stockholders in the merger. See “The Merger—Litigation Relating to the Merger” beginning on page 100 of this proxy statement/prospectus for more information about the settlement of the stockholder litigation challenging the merger.

SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF MSCI

The following table presents selected historical consolidated financial data of MSCI. The selected financial data of MSCI for each of the years ended November 30, 2009, 2008 and 2007 and as of November 30, 2009 and 2008 are derived from MSCI’s audited consolidated financial statements and related notes contained in its Annual Report on Form 10-K for the year ended November 30, 2009, which is incorporated by reference into this proxy statement/prospectus. The selected financial data of MSCI for each of the years ended November 30, 2006 and 2005 and as of November 30, 2007, 2006 and 2005 have been derived from MSCI’s audited consolidated financial statements for such years, which have not been incorporated into this proxy statement/prospectus by reference. The selected financial condition data of MSCI as of February 28, 2010 and the selected income statement data of MSCI for the three months ended February 28, 2010 and 2009 are derived from MSCI’s unaudited condensed consolidated financial statements and related notes contained in its Quarterly Report on Form 10-Q for the quarterly period ended February 28, 2010, which is incorporated by reference into this proxy statement/prospectus. The selected financial condition data of MSCI as of February 28, 2009 is derived from MSCI’s unaudited condensed consolidated financial statements and related notes contained in its Quarterly Report on Form 10-Q for the quarterly period ended February 28, 2009, which has not been incorporated into this proxy statement/prospectus by reference. MSCI’s management believes that the company’s interim unaudited financial statements have been prepared on a basis consistent with its audited financial statements and include all normal and recurring adjustments necessary for a fair presentation of the results for each interim period.

The information in the following table is only a summary and is not indicative of the results of future operations of MSCI. You should read the following information together with MSCI’s Annual Report on Form 10-K for the year ended November 30, 2009, MSCI’s Quarterly Report on Form 10-Q for the quarterly period ended February 28, 2010 and the other information that MSCI has filed with the Securities and Exchange Commission, which is referred to in this proxy statement/prospectus as the SEC, and incorporated by reference into this proxy statement/prospectus. See “Where You Can Find More Information” beginning on page 155 of this proxy statement/prospectus.

SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF RISKMETRICS

The following table presents selected historical consolidated financial data of RiskMetrics. The selected financial data of RiskMetrics for each of the three months ended December 31, 2009 and 2008 are derived from unaudited data contained in its Annual Report on Form 10-K for the year ended December 31, 2009. The selected financial data of RiskMetrics for the years ended December 31, 2009, 2008 and 2007 and as of December 31, 2009 and 2008 are derived from RiskMetrics’ audited consolidated financial statements and related notes contained in its Annual Report on Form 10-K for the year ended December 31, 2009, which is incorporated by reference into this proxy statement/prospectus. The selected financial data of RiskMetrics for each of the years ended December 31, 2006 and 2005 and as of December 31, 2007, 2006 and 2005 have been derived from RiskMetrics’ audited consolidated financial statements for such years, which have not been incorporated into this proxy statement/prospectus by reference.

The information in the following table is only a summary and is not indicative of the results of future operations of RiskMetrics. You should read the following information together with RiskMetrics’ Annual Report on Form 10-K for the year ended December 31, 2009 and the other information that RiskMetrics has filed with the SEC and incorporated by reference into this proxy statement/prospectus. See “Where You Can Find More Information” beginning on page 155 of this proxy statement/prospectus.

Consolidated Statements of Operations Data

Consolidated Balance Sheet Data

COMPARATIVE HISTORICAL AND UNAUDITED PRO FORMA PER SHARE DATA

The following table sets forth selected historical and unaudited pro forma combined per share information of MSCI and RiskMetrics.

Pro Forma Combined Per Share Information of the Combined Company. The unaudited pro forma combined per share information of the combined company set forth below gives effect to the merger under the acquisition method of accounting, as if the merger had been effective on December 1, 2008, the first day of MSCI’s fiscal year ended November 30, 2009, in the case of income from continuing operations and cash dividends data and, at November 30, 2009, in the case of book value per share data, and assuming that each outstanding share of RiskMetrics common stock had been converted into shares of MSCI Class A common stock based on the exchange ratio (0.1802 shares of MSCI Class A common stock for each share of RiskMetrics common stock). The exchange ratio does not include the $16.35 cash portion of the merger consideration.

The pro forma per share balance sheet information combines MSCI’s February 28, 2010 unaudited condensed consolidated statement of financial condition with RiskMetrics’ December 31, 2009 consolidated balance sheet. The pro forma per share income statement information for the fiscal year ended November 30, 2009 combines MSCI’s audited consolidated statement of income for the fiscal year ended November 30, 2009 with RiskMetrics’ consolidated statement of operations for the fiscal year ended December 31, 2009. The pro forma per share income statement information for the three months ended February 28, 2010 combines MSCI’s unaudited condensed consolidated statement of income for the three months ended February 28, 2010 with RiskMetrics’ unaudited quarterly financial data for the three months ended December 31, 2009.

The acquisition method of accounting is based on Accounting Standards Codification (ASC) Subtopic 805-10, Business Combinations, and uses the fair value concepts defined in ASC Subtopic 820-10, Fair Value Measurements and Disclosures, which MSCI has adopted as required. Acquisition accounting requires, among other things, that most assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. The acquisition accounting is dependent upon certain valuations of RiskMetrics’ assets and liabilities and other studies that have yet to commence or progress to a stage where there is sufficient information for a definitive measurement. Accordingly, the pro forma adjustments reflect the assets and liabilities of RiskMetrics at their preliminary estimated fair values. Differences between these preliminary estimates and the final acquisition accounting will occur and these differences could have a material impact on the unaudited pro forma combined per share information set forth in the following table.

The unaudited pro forma combined per share information of the combined company does not purport to represent the actual results of operations that MSCI would have achieved had the companies been combined during these periods or to project the future results of operations that MSCI may achieve after the merger.

Historical Per Share Information of MSCI and RiskMetrics. The historical per share information of MSCI below is derived from MSCI’s audited consolidated financial statements as of, and for the year ended, November 30, 2009 and MSCI’s unaudited condensed consolidated financial statements as of, and for the three months ended, February 28, 2010. The historical per share information of RiskMetrics below is derived from RiskMetrics’ audited consolidated financial statements as of, and for the year ended, December 31, 2009 and RiskMetrics’ unaudited condensed consolidated financial data as of, and for the quarter ended, December 31, 2009, the last quarter of RiskMetrics’ fiscal year ended December 31, 2009.

Equivalent Pro Forma Combined Per Share Information. The unaudited equivalent pro forma combined per share amounts below are calculated by multiplying the unaudited pro forma combined per share amounts of MSCI by the exchange ratio of 0.1802.

Generally. You should read the below information in conjunction with the selected historical consolidated financial information, included elsewhere in this proxy statement/prospectus, and the historical consolidated financial statements of MSCI and RiskMetrics and related notes that have been filed with the SEC, certain of which are incorporated into this proxy statement/prospectus by reference. See “Selected Historical Consolidated

Financial Data of MSCI”, “Selected Historical Consolidated Financial Data of RiskMetrics” and “Where You Can Find More Information” beginning on pages 21, 23 and 155, respectively, of this proxy statement/ prospectus. The unaudited MSCI pro forma combined per share information is derived from, and should be read in conjunction with, the unaudited pro forma condensed combined financial statements and related notes included in this proxy statement/prospectus. See “MSCI and RiskMetrics Unaudited Pro Forma Condensed Combined Financial Information” beginning on page 29 of this proxy statement/prospectus.