The Parties

NYSE Euronext (see page 134)

NYSE Euronext is a holding company created by the combination of the businesses of NYSE Group, Inc. and Euronext N.V., which was completed on April 4, 2007. NYSE Euronext is the world’s leading and most liquid exchange group with both the highest average daily value of cash trading and the largest market capitalization of listed operating companies of all exchanges. NYSE Euronext offers a diverse array of financial products and services, and operates six cash equities and six derivatives exchanges in six countries and two continents. NYSE Euronext is a world leader for trading in cash equities, exchange traded funds (“ETFs”) and other structured products, and equity and interest rate derivatives, as well as the creation and global distribution of market information related to trading in these products. NYSE Euronext is the largest listing venue in the world, home to corporations representing over $30 trillion in market capitalization (as of December 31, 2007). In the United States, NYSE Euronext operates NYSE and NYSE Arca, leading providers of securities listing, trading and market data products and services. In Europe, NYSE Euronext operates cash equities and derivatives exchanges through its subsidiaries in Belgium, France, the Netherlands and Portugal, in addition to services for derivatives markets in the United Kingdom. NYSE Euronext also operates a globally-distributed connectivity network and provides commercial trading and information technology solutions for customers and other exchanges. Representing a combined $30.4 trillion total market capitalization of listed operating companies and average daily trading value of approximately $141.2 billion (as of December 31, 2007), NYSE Euronext seeks to provide the highest standards of market quality and integrity, innovative products and services to investors, issuers, and all users of its markets. For the year ended December 31, 2007, based on financial

statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”), NYSE Euronext generated $4,158 million in total revenues and $643 million in net income.

NYSE Euronext’s principal executive offices are located at 11 Wall Street, New York, New York 10005 and the telephone number is (212) 656-3000.

Amsterdam Merger Sub, LLC

Amsterdam Merger Sub, LLC, a Delaware limited liability company (which we refer to in this document as “merger sub”), is a wholly owned subsidiary of NYSE Euronext that was formed for the purpose of completing the mergers. Merger sub has not engaged in any business except activities incidental to its organization and in connection with the transactions contemplated by the merger agreement.

The Amex Membership Corporation

The Amex Membership Corporation (which we refer to in this document as “MC”), a New York Type A not-for-profit corporation, is the holding company of Amex.

MC’s principal executive offices are located at 86 Trinity Place, New York, New York 10006 and the telephone number is (212) 306-1000.

American Stock Exchange LLC (see page 259)

American Stock Exchange LLC (which we refer to in this document as “Amex”) operates a securities market that conducts trading through an auction market structure that has both floor-based and electronic features. Amex offers trading across a full range of equities, options and ETFs. In addition to its role as a national equities market in the United States, Amex has been the pioneer of ETFs, responsible for bringing the first domestic ETF product to market in 1993 and continues to have the largest number of ETF listings of any exchange in the United States. Amex also operates one of seven options exchanges in the United States, which trades options on domestic and

foreign stocks, American depositary receipts (“ADRs”), broad-based, industry and sector and international indexes, ETFs and Holding Company Depositary Receipts (“HOLDRs”). Amex also offers trading in structured products and disseminates market data.

Amex generates revenue primarily from execution services (transaction charges), issuer services (listing fees) and market information services (primarily tape revenue). Amex also generates revenue from registration fees, assessment fees and other revenues, including fees earned from trading floor services provided to members, fees from index calculation services, contractual fees derived from trademark licenses to use Amex-owned indexes and other services.

Amex has incurred operating losses each year since 2001. For the year ended December 31, 2007, Amex generated operating revenues of $178.5 million and a net loss of $32.4 million.

Amex’s principal executive offices are located at 86 Trinity Place, New York, New York 10006 and the telephone number is (212) 306-1000.

AMC Acquisition Sub, Inc.

AMC Acquisition Sub, Inc., a Delaware corporation, is a wholly owned subsidiary of MC that was formed for the purpose of acquiring the interests in Amex formerly held by Financial Industry Regulatory Authority, Inc. or FINRA (formerly known as National Association of Securities Dealers, Inc. or NASD) in 2004. AMC Acquisition Sub, Inc. has not engaged in any business except activities incidental to its organization and in connection with the acquisition of interests in Amex from FINRA.

American Stock Exchange Holdings, Inc.

American Stock Exchange Holdings, Inc., a Delaware corporation (which we refer to in this document as “Holdings”), is a wholly owned subsidiary of MC that was formed for the purpose of completing the mergers. Holdings has not engaged in any business except activities incidental to its organization and in connection with the transactions contemplated by the merger agreement.

American Stock Exchange 2, LLC

American Stock Exchange 2, LLC, a Delaware limited liability company (which we refer to in this document as “Amex merger sub”), is a wholly owned subsidiary of Holdings that was formed for the purpose of completing the mergers. Amex merger sub has not engaged in any business except activities incidental to its organization and in connection with the transactions contemplated by the merger agreement.

Special Meeting of MC Members (see page 47)

A special meeting of the members will be held on June 17, 2008, at 8:30 a.m. Eastern Standard Time, at 86 Trinity Place, New York, NY 10006. You may vote at the special meeting or any adjournments thereof if you are a Voting Member of record and in good standing as of the close of business on May 5, 2008, the record date for the special meeting. On each proposal at the special meeting, each Voting Member may cast one vote for each membership the Voting Member has the right to vote. The presence, in person or by proxy, of a majority of the memberships entitled to vote is necessary to constitute a quorum at the special meeting.

Proposal to Approve the Merger Agreement. The merger agreement must be approved by the affirmative vote of at least two-thirds of the votes cast by the persons entitled to exercise voting rights thereon at a duly convened meeting where a quorum is present. The affirmative vote also must represent a majority of the votes held by persons entitled to exercise voting rights.

Proposal to Adjourn or Postpone the Meeting. To approve any proposal to adjourn or postpone the meeting, should such a proposal be made at the meeting, members holding a majority of the memberships present or represented by proxy at the meeting must approve such proposal.

Other Proposals. The approval of any other proposals presented at the special meeting generally requires the affirmative vote of a majority of the votes cast by the members at the special meeting.

What MC Members Will Receive in the Mergers (see page 104)

Upon the completion of the mergers, holders of regular memberships and OPMs will receive $260

million in NYSE Euronext common stock in the aggregate. Specifically, each holder of a regular membership is expected to receive approximately $311,923 in shares of NYSE Euronext common stock for such membership and each holder of an OPM is expected to receive approximately $275,923 in shares of NYSE Euronext common stock for each such membership as set forth below. In determining the $36,000 difference, the board of directors of MC and the board of governors of Amex considered that OPMs have more limited trading rights and a less favorable liquidation preference than regular memberships and have traded historically at a lower price than regular memberships, and that OPM holders had most recently been offered an opportunity to upgrade their OPM to a regular membership for $36,000. The estimated dollar value of the shares of NYSE Euronext common stock to be received by each member has been calculated based on the 807 regular memberships and 30 OPMs currently outstanding. The actual number of shares received by each member will be calculated by dividing the dollar amount of NYSE Euronext common stock such member is entitled to receive by the volume-weighted average price of NYSE Euronext common stock during the 15 consecutive trading days leading up to the date on which NYSE Euronext’s acquisition of the business of Amex is completed.

In addition, the holders of memberships will also be entitled to receive contingent consideration in the form of additional shares of NYSE Euronext common stock based on the net proceeds, if any, from the sale of the Amex headquarters, if such sale occurs within a specified period of time and certain other conditions are satisfied. The contingent consideration, if any, will be distributed equally with respect to each regular membership and OPM. Shares of NYSE Euronext common stock that are issued in the mergers will be listed on the NYSE and Euronext Paris and will be freely transferable subject to the ownership and voting limitations contained in the NYSE Euronext organizational documents.

Merger Consideration

As a result of the mergers, pursuant to the merger agreement, each regular membership of MC (each a “regular membership”) will be converted into

the right to receive, following completion of the mergers, the “regular merger consideration,” which is a number of shares of NYSE Euronext common stock equal to the quotient obtained by dividing:

(which quotient we refer to as the “dollar value of the regular merger consideration”)

As a result of the mergers, pursuant to the merger agreement, each OPM will be converted into the right to receive, following completion of the mergers, the “OPM merger consideration,” which is a number of shares of NYSE Euronext common stock equal to the quotient obtained by dividing:

The “regular merger consideration” and the “OPM merger consideration” are each generally referred to as the “merger consideration.”

Contingent Consideration

The merger agreement also provides that if 86 Trinity Place, New York, NY and 22 Thames Street, New York, NY (which we refer to in this document as the “Amex headquarters”) are sold at any time before the date which is four years and 240 days following the completion of the mergers, and certain other conditions are met, MC members (comprised of holders of regular memberships and OPMs) will be entitled to receive, as additional merger consideration, a number of shares of NYSE Euronext common stock equal to the quotient (rounded down to the nearest whole share) obtained by dividing:

We refer to this as the “contingent consideration.” It is important to note that in addition to the other restrictions on the contingent consideration described in the merger agreement, the right to receive the contingent consideration is non-transferable and non-assignable except by operation of law and that the aggregate number of shares of NYSE Euronext common stock that MC members can receive as contingent consideration is capped at the aggregate number (as appropriately adjusted for any stock splits, combinations, reclassifications or other similar actions occurring after the completion of the mergers) of shares of NYSE Euronext common stock received by MC members at the effective time of the mergers. If the aggregate number of shares of NYSE Euronext common stock to be issued as contingent consideration exceeds the cap, the number of shares that each MC membership will receive as contingent consideration will be reduced on a pro rata basis such that the resulting aggregate number of NYSE Euronext shares received by MC members as contingent consideration does not exceed this cap.

Amex has retained the brokerage firm of Cushman & Wakefield, Inc. to market the Amex headquarters.

Who Will Receive the Merger Consideration and Contingent Consideration (see page 100)

Only regular members and options principal members are equity owners of MC, and, therefore only regular members and options principal members will be entitled to receive the consideration described above and described in more detail under “The Merger Agreement—Consideration to be Received by MC Members.” Therefore, if you are a member who owns a membership immediately prior to the effective time of the Holdings merger, you will receive NYSE Euronext common stock in exchange for your membership. If you are a member immediately prior to the effective time of the Holdings merger, you will also be entitled to receive

the contingent consideration in the form of additional shares of NYSE Euronext common stock based on the net proceeds, if any, from the sale of the Amex headquarters, if such sale occurs within a specified time frame and certain other conditions are satisfied. For a description of other material conditions to MC members receipt of the contingent consideration, see “The Merger Agreement—Consideration to be Received by MC Members—Contingent Consideration” and “The Merger Agreement—Contingent Consideration Upon Sale of the Amex Headquarters.” Lessees of memberships, allied members, associate members and limited trading permit holders will not be entitled to receive any NYSE Euronext common stock or any other form of consideration in connection with the mergers. In addition, effective upon the completion of the mergers, lessees of memberships will cease to have any trading rights under the lease. Access to Amex’s trading facilities will be made available exclusively through trading permits newly issued by Amex (currently known as Amex merger sub).

Structure of the Mergers (see page 103)

The merger agreement provides that MC will demutualize and the business of Amex will be acquired by a subsidiary of NYSE Euronext through the following mergers (which we refer to as the “mergers”):

In the Holdings merger, each membership will be converted into the type and amount of consideration described under “—What MC Members Will Receive in the Mergers” above, except that, instead of shares of NYSE Euronext common stock, MC members will receive shares of Holdings common stock, par value $0.01 per share (“Holdings common stock”). As a result of the NYSE Euronext/Amex merger, the holders of issued and outstanding shares of Holdings common stock will be entitled to the right to receive (1) one share of NYSE Euronext common stock for each share of Holdings common stock they own and (2) the contingent consideration, if any, for each membership held immediately prior to the Holdings merger.

MC and Amex’s Reasons for the Mergers; Recommendation for the Mergers (see page 69)

The board of directors of MC and the board of governors of Amex considered a number of factors pertaining to the NYSE Euronext/Amex merger, including (i) financial factors, such as the historical performance of Amex, significant expenses, the greater liquidity of NYSE Euronext common stock, financial terms of the merger agreement and the marketing presentations containing a range of preliminary valuations of the Amex headquarters, (ii) operational factors, such as the unsuccessful pursuit of other potential strategic alliances and mergers and the challenges to Amex’s business in continuing to operate as an independent company, (iii) strategic rationale, such as the expectation that Amex would be able to take advantage of NYSE Euronext’s leading reputation and (iv) other terms of the transaction. In addition, the board of directors of MC and the board of governors of Amex also considered the risks of the NYSE Euronext/Amex merger, including the risk that the merger might not be completed in a timely manner or at all, the risk of disruption to Amex’s business, the cap on contingent consideration, the fees and expenses, the risk that expected synergies and cost savings may not be realized and the risks involved in integration. Based on such reasons, which are set forth in more detail in “The Mergers—MC and Amex’s Reasons for the Mergers; Recommendation of the Mergers,” all five members of the board of directors of MC and 10 of the 11 members of the board of governors of Amex in attendance voted to recommend that members vote “FOR” the approval and adoption of the merger agreement and the transactions contemplated by the merger agreement. In addition, the board of directors of MC and the board of governors of Amex recommend that the members vote “FOR” any proposal that may be made by the Chairman of the board of directors of MC or his or her designee to adjourn or postpone the special meeting for the purpose of soliciting additional proxies with respect to the proposal to adopt the merger agreement.

Interests of MC Directors, Amex Governors and Executive Officers in the Mergers (see page 89)

MC members should be aware that certain governors and officers of Amex have agreements or arrangements that provide them with interests in the

mergers that may be different from, in addition to, or in conflict with, those of MC members. These interests may include, but are not limited to, the treatment in the NYSE Euronext/Amex merger of certain employment agreements and Amex’s Supplemental Executive Retirement Plan, and the indemnification of former Amex governors and officers by NYSE Euronext. In particular, Mr. Wolkoff may be entitled to certain change of control payments in the event of termination, Mr. Shagoury may be entitled to a retention bonus as well as certain change of control payments in the event of termination and Messrs. Warner and Seetin may be entitled to certain severance payments. While such terms were not negotiated in connection with the NYSE Euronext/Amex merger, such payments may be triggered by the NYSE Euronext/Amex merger. Please see “The Mergers—Interests of Officers and directors in the Mergers” for more information on these payments.

In addition, certain members of MC board of directors and Amex board of governors own or lease memberships in Amex or own, lease, or are affiliated with or employed by, entities that own or lease memberships in Amex. In particular, each of Dr. Frost and Messrs. Fischer, Frank, Hyde, Koondel, Olah, Pohs, Sheridan, Silver and Whitman either owns or leases a membership or owns, leases, or is affiliated with or employed by, an entity that owns or leases a membership and either the individual himself/herself or the membership owner entity will have the right to receive the merger consideration upon the completion of the NYSE Euronext/Amex merger and may have the right to receive the contingent consideration, if any, at such time as provided in the merger agreement.

As of May 7, 2008, directors of MC and governors of Amex held memberships entitling them to cast an aggregate of 47 votes on the proposal, representing approximately 5.62% of the total membership votes that may be cast. None of the directors of MC nor governors of Amex hold OPMs.

Opinions of Financial Advisors (see page 74)

In connection with the proposed mergers, NYSE Euronext retained Lehman Brothers to act as a financial advisor and to deliver an opinion in connection with the proposed mergers. Lehman

Brothers rendered to NYSE Euronext board of directors an opinion, dated January 17, 2008, to the effect that, as of the date of the opinion and based upon and subject to the considerations and limitations set forth in the opinion, the aggregate consideration to be paid by NYSE Euronext in the mergers is fair, from a financial point of view, to NYSE Euronext stockholders. Lehman Brothers addressed its opinion to NYSE Euronext’s board of directors, and the opinion does not constitute a recommendation to any person as to how to act with respect to the mergers.

In connection with the proposed mergers, the board of directors of MC retained Morgan Stanley and Co. Incorporated (“Morgan Stanley”) to act as its financial advisor and received an opinion from Morgan Stanley, dated January 17, 2008, as to the fairness, from a financial point of view, of the consideration to be received by the MC members who receive shares of Holdings common stock pursuant to the merger agreement to such MC members. For the purposes of rendering its opinion, Morgan Stanley assumed, per the instructions of the MC board of directors, that the contingent consideration will consist of aggregate net building sale proceeds of not less than $56 million. There can be no assurance that there will be any net building sale proceeds or, if there are net building sale proceeds, that this assumption is indicative of what the actual net building sale proceeds will be. Morgan Stanley addressed its opinion to MC’s board of directors, and the opinion does not constitute a recommendation to any member as to how to vote or as to any other action that a member should take relating to the mergers.

The full text of the written opinions of Lehman Brothers and Morgan Stanley are included as Annexes B and C, respectively, to this proxy statement and prospectus, and are incorporated herein by reference. You are urged to read each of the opinions carefully and in their entirety for a description of the procedures followed, matters considered and limitations on the review undertaken.

Material U.S. Federal Income Tax Consequences of the Mergers (see page 92)

It is a condition to the obligation of NYSE Euronext to consummate the NYSE Euronext/Amex merger that it receive a private letter ruling from the Internal Revenue Service (“IRS”) or an opinion from

its counsel, dated as of the closing date of the NYSE Euronext/Amex merger, in either case to the effect that the NYSE Euronext/Amex merger will be treated for U.S. federal income tax purposes as a reorganization within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Code”). It is a condition to the obligation of MC to consummate the NYSE Euronext/Amex merger that it receive a private letter ruling from the IRS and/or an opinion of its counsel, dated as of the closing date of the NYSE Euronext/Amex merger, in either case or collectively to the effect that (i) the AMCAS merger will be treated for U.S. federal income tax purposes as a reorganization within the meaning of Section 368(a) of the Code and/or as a tax-free liquidation under Sections 332 and 337 of the Code, (ii) the Holdings merger will be treated for U.S. federal income tax purposes as a reorganization within the meaning of Section 368(a) of the Code and no gain or loss will be recognized by holders of MC memberships upon their exchange of MC memberships for Holdings common stock pursuant to the Holdings merger, (iii) the NYSE Euronext/Amex merger will be treated for U.S. federal income tax purposes as a reorganization within the meaning of Section 368(a) of the Code and no gain or loss will be recognized by holders of Holdings commons stock upon their exchange of Holdings common stock for NYSE Euronext common stock pursuant to the NYSE Euronext/Amex merger, except with respect to cash received in lieu of fractional shares of NYSE Euronext common stock and any portion of the contingent consideration that is required to be treated as interest for U.S. federal income tax purposes.

In addition, in connection with the filing of the registration statement of which this proxy statement/prospectus is a part, each of NYSE Euronext and MC has received a legal opinion, from Wachtell, Lipton, Rosen & Katz and Milbank, Tweed, Hadley & McCloy LLP, respectively, to the same effect as the opinions described above. Accordingly, a holder of an MC membership generally will not recognize income, gain or loss for U.S. federal income tax purposes upon the receipt of NYSE Euronext common stock solely in exchange for its MC membership, except with respect to (1) cash received in lieu of fractional shares of NYSE Euronext common stock and (2) any portion of the contingent consideration treated as imputed interest.

You should read “The Mergers—Material U.S. Federal Income Tax Consequences” for a more

complete discussion of the U.S. federal income tax consequences of the mergers. Please consult your tax advisor for a full understanding of the tax consequences of the mergers to you.

Regulatory Approvals and Conditions to Completion of the Mergers (see page 96)

Competition and Antitrust

NYSE Euronext and MC have each agreed to use its reasonable best efforts to obtain all regulatory approvals required to complete the transactions contemplated by the merger agreement. Under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”), and the rules promulgated thereunder by the Federal Trade Commission (the “FTC”), the mergers may not be completed until notification and report forms have been filed with the FTC and the Antitrust Division of the Department of Justice (the “DOJ”), and applicable waiting periods have expired or been terminated. On February 4, 2008 and February 6, 2008, respectively, NYSE Euronext and MC filed notification and report forms under the HSR Act with the FTC and the Antitrust Division of the DOJ. On March 6, 2008, NYSE Euronext and Amex received a notification from the FTC that early termination of the applicable waiting period under the HSR Act had been granted.

Securities and Other Regulatory Authorities

SROs such as NYSE, NYSE Arca and Amex, are required to file proposed rule changes with the SEC, and in many cases the SEC has the right to approve, pursuant to Section 19 of the Exchange Act and the rules and regulations thereunder. Changes to the organizational documents of any SRO constitute rule changes and changes to the organizational documents of entities that directly or indirectly control SROs may constitute rule changes. NYSE, NYSE Arca (if required) and Amex intend to file proposed rule changes with the SEC relating to certain elements of the proposed organization and operations described in this document.

L’Autorité des marchés financiers (“AMF”). NYSE Euronext may be required to file a registration document with the AMF in connection

with obtaining approval to list the NYSE Euronext common stock to be issued as merger consideration and contingent consideration on Euronext Paris. Any registration document filed with the AMF will be subject to the approval of the AMF.

European Regulators. Euronext’s College of Regulators, which includes the Chairmen of the AMF, the Netherlands Authority for the Financial Markets (Autoriteit Financiële Markten), the Belgian Banking, Finance, and Insurance Commission (Commission Bancaire, Financière, et des Assurances), the Portuguese Securities Commission (Comissão do Mercado de Valores Mobiliários), and the U.K. Financial Services Authority has the right to approve certain changes to the organizational documents of NYSE Euronext and its subsidiaries to the extent that such changes affect NYSE Euronext’s European exchanges and may have the right to approve the changes to the NYSE Euronext bylaws resulting from the mergers.

In addition to the regulatory approvals noted above, the mergers are subject to the receipt of all other governmental approvals or the making of all other required governmental filings, the failure of which to be obtained or made, individually or in the aggregate, would reasonably be expected to result in a “detriment” as defined in the merger agreement.

While NYSE Euronext and Amex believe that they will receive the requisite regulatory approvals for the mergers, they can give no assurance that a challenge to the mergers will not be made or, if made, would be unsuccessful.

See “The Merger Agreement—Conditions to Completing the Mergers.”

Member Approval and Other Conditions

The mergers are also subject to the satisfaction or waiver of other conditions as provided in the merger agreement, including the approval of the MC members. See “The Merger Agreement—Conditions to Completing the Mergers.” Subject to the satisfaction or waiver of the conditions set forth in the merger agreement, NYSE Euronext and MC expect to complete the mergers in the third quarter of 2008.

Absence of Appraisal Rights (see page 100)

Under the New York Not-for-Profit Corporation Law, members are not entitled to any appraisal rights in connection with the Holdings merger. Under the Delaware General Corporation Law, Holdings stockholders are not entitled to any appraisal rights in connection with the NYSE Euronext/Amex merger.

Directors and Management of NYSE Euronext Following the Mergers (see page 123)

The composition of the NYSE Euronext board of directors and management committee is not expected to change as a result of the mergers.

Third-Party Acquisition Proposals (see page 110)

MC, AMC Acquisition Sub, Inc., Holdings, Amex and Amex merger sub have agreed that they will not, nor will they permit any of their respective subsidiaries or any of their or their subsidiaries’ respective officers, directors, employees, agents and representatives to, directly or indirectly:

Notwithstanding the foregoing, MC may, prior to the receipt of its members’ approval of the mergers, in response to a bona fide, written and unsolicited Takeover Proposal:

provided, in each case, that the board of directors of MC determines in good faith after consultation with its outside counsel and financial advisor, that (i) furnishing such information or participating in such discussions would be reasonably necessary to perform its fiduciary duties under applicable law and (ii) the Takeover Proposal is or is reasonably likely to lead to a “Superior Proposal” (as defined in the merger agreement).

MC has also agreed that its board of directors will not change its recommendation with respect to the mergers or approve any alternative agreement. Notwithstanding the previous sentence, at any time prior to the MC member approval, the MC board of directors may make a change in recommendation if it determines, in good faith and in accordance with advice from its outside counsel and financial advisor, that such change is reasonably necessary for it to perform its fiduciary duties and may, in response to a Superior Proposal, make a change in recommendation and recommend such Superior Proposal.

The merger agreement requires MC to call, give notice of and hold a meeting of its members for the purposes of obtaining the MC member approval. Even if the MC board of directors effects a “change in recommendation,” as permitted under the circumstances described above, it is nonetheless required to submit the merger agreement to its members for approval, unless the merger agreement has been terminated in accordance with its terms prior to the MC special meeting.

Termination of the Merger Agreement; Termination Fee and Expense Reimbursement (see page 115)

Termination Rights

NYSE Euronext and MC may terminate the merger agreement at any time prior to the completion of the mergers by mutual consent. In addition, either NYSE Euronext or MC may terminate the merger agreement at any time prior to the completion of the mergers if:

NYSE Euronext may also terminate the merger agreement at any time prior to the completion of the mergers if:

Termination Fees and Expenses

MC must pay a termination fee of $10 million to NYSE Euronext if the merger agreement is terminated because:

If the merger agreement is terminated because of (1) MC’s uncured breach of the merger agreement, which prevents the satisfaction of NYSE Euronext’s relevant closing conditions; (2) the failure of MC’s members to adopt the merger agreement at the members’ meeting; or (3) the mergers not having been completed by the outside date and a vote of the MC members not having occurred; and, in each case, a Takeover Proposal (as described above) has been made at any time from the date of the merger agreement and prior to the special meeting of MC members in the case of clause (2) and the termination of the merger agreement in the case of clauses (1) and (3), then MC must pay one half of the termination fee ($5 million) to NYSE Euronext. Then, if MC enters into a definitive agreement to consummate or consummates the transactions contemplated by the Takeover Proposal within 18

months of termination of the merger agreement, MC must pay an additional one half of the termination fee ($5 million) to NYSE Euronext.

In addition, if the merger agreement is terminated because:

MC must reimburse NYSE Euronext for its out-of-pocket fees and expenses incurred in connection with the mergers, but in no event shall MC pay more than a total of $10 million (including any termination fee) to NYSE Euronext.

Also, if the merger agreement is terminated because of NYSE Euronext’s uncured breach of the merger agreement, it shall reimburse MC for its expenses in connection with the mergers, up to $10 million.

Stock Exchange Listing and Stock Prices (see page 97)

NYSE Euronext common stock is listed on the NYSE and Euronext Paris under the symbol “NYX.” NYSE Euronext intends to apply to list the NYSE Euronext common stock to be issued in the mergers on the NYSE and on Euronext Paris.

Membership Prices (see page 97)

MC memberships are not traded or quoted on a stock exchange or quotation system. All transfers of memberships, including transfers through private sales, currently must be processed through Amex’s membership department. Amex records the sale prices of memberships.

Certain Differences in the Rights of a Member Before and After the Mergers (see page 277)

MC members will become NYSE Euronext stockholders after the closing of the mergers, and their rights as stockholders will be governed by NYSE Euronext’s certificate of incorporation and bylaws and by Delaware law. As a result, there will be material differences between the current rights of MC members as owners of MC membership interests and the rights they can expect to have as NYSE Euronext stockholders. For example, MC is a New York Type A not-for-profit corporation governed by the New York Not-for-Profit Corporation Law, whereas NYSE Euronext is a for-profit publicly held corporation governed by Delaware General Corporation Law.

In addition, there will be voting and ownership limitations on NYSE Euronext common stock. The NYSE Euronext certificate of incorporation contains provisions prohibiting any person, acting either alone or together with its related persons (as defined in the NYSE Euronext certificate of incorporation and described under “Description of NYSE Euronext Capital Stock—Ownership and Voting Limits on NYSE Euronext Capital Stock”), from voting more than 10% of the then outstanding votes entitled to be cast on any matter, acquiring the ability to vote more than 10% of the then outstanding votes entitled to be cast on any matter by virtue of agreements entered into by other persons not to vote shares of NYSE Euronext capital stock, or owning beneficially shares of stock of NYSE Euronext representing in the aggregate more than 20% of the then outstanding votes entitled to be cast on any matter unless (1) the NYSE Euronext board resolves to expressly permit such voting or ownership in accordance with the standard for approving such voting or ownership set forth in the NYSE Euronext certificate of incorporation (which provides, among other limitations, that the NYSE Euronext board may not waive the ownership or voting limitations above the 20% level for members or trading permit holders of NYSE, NYSE Arca, Inc., NYSE Equities, Inc., and following the mergers, Amex, or their related persons) and (2) such resolution has been approved by the relevant European regulators and the SEC.

In addition, the common stock of NYSE Euronext that MC members receive in the NYSE

Euronext/Amex merger will not entitle them to trade on Amex or on any other exchange. Physical and electronic access to Amex’s trading facilities will be subject to such limitations and requirements as will be specified in the Amex rules, which will become effective upon the completion of the mergers and will be made available to individuals and organizations that obtain a trading permit from Amex. For a period of one year following the completion of the mergers, assuming the market structure of Amex remains substantially the same as it was on the date of the merger agreement, NYSE Euronext will make Amex equity trading permits available at a price no greater than the cost of licenses to trade on the NYSE and to make Amex options trading permits available at a price no greater than the price of NYSE Arca, Inc. options trading permits. NYSE Euronext currently anticipates that it will make an unlimited number of such Amex equity and options trading permits available.

Following its acquisition of Amex, NYSE Euronext currently intends to (1) maintain the Amex listing with respect to Amex equities and options; (2) relocate the Amex options and equities trading facilities to the NYSE trading floor, utilizing the trading systems based on those of NYSE Arca, Inc. and NYSE, respectively; (3) move Amex listed ETFs and certain structured products to the NYSE Arca, Inc. listing and trading system (which is all electronic); and (4) move Amex listed bonds to the NYSE listing and NYSE bond trading system (which is all electronic).

Termination of the Gratuity Fund (see page 101)

Currently, the Amex constitution provides for a Gratuity Fund. Upon the completion of the mergers, Amex merger sub will not have a Gratuity Fund. Following the mergers, there will be no further payment of gratuities other than those related to the deaths that occurred prior to the completion of the mergers. Upon completion of the NYSE Euronext/Amex merger, Amex merger sub currently expects to allocate the assets then remaining in the Gratuity Fund (net of any administrative expenses incurred in the distribution of such amount), first to pay out the death benefits that are accrued but unpaid as of the completion of the NYSE Euronext/Amex merger, and then to distribute the remaining balance, if any, to the participants that existed immediately prior

to the SRO merger. The amounts paid to each participant, if any, will vary based on the length of time such person was a participant in the Gratuity Fund. If the assets remaining in the Gratuity Fund are insufficient, families of the deceased participants may see a reduction in death benefits. As of March 31, 2008, there was $254,302 remaining in the Gratuity Fund before the above-mentioned expenses.

Fees and Expenses

NYSE Euronext and MC will incur significant legal, accounting and other transaction fees and other costs related to the mergers. Some of these costs are payable regardless of whether the mergers are completed. Approximately $6.3 million (plus fees to be mutually agreed in respect of the contingent consideration) of Morgan Stanley’s fee, and $2 million of Lehman Brothers’s fee is contingent upon the completion of the mergers. In the event that the mergers are not completed, Morgan Stanley will be entitled to a fee of $450,000. In addition, Lehman Brothers received a fee of $1 million, upon delivery of its fairness opinion. In general and except as otherwise specified in the merger agreement, all costs and expenses incurred in connection with the merger agreement will be paid by the party incurring such expenses, except that those expenses incurred in connection with printing and mailing this proxy statement/prospectus, all filing and other fees that are paid to the SEC in connection with the filing of the registration statement of which this proxy statement/prospectus forms a part, and all filing fees associated with the filing of the notification and report forms under the HSR Act will be borne equally by MC and NYSE Euronext.

Share Repurchases (see page 99)

Subject to applicable laws and regulations, NYSE Euronext may announce and/or engage in share repurchases of NYSE Euronext common stock prior to or following the completion of the mergers. In March 2008, NYSE Euronext’s board of directors authorized the repurchase of up to $1 billion of NYSE Euronext common stock. Under the program, NYSE Euronext may repurchase stock from time to time at the discretion of management in open market or privately negotiated transactions or otherwise, subject to applicable U.S. or European laws, regulations and approvals, strategic considerations, market conditions and other factors. The stock

repurchase program does not obligate NYSE Euronext to repurchase any dollar amount or number of shares of NYSE Euronext common stock and any such repurchases will be made in compliance with the applicable laws and regulations, including rules

and regulations of the SEC and applicable EU regulations and regulations of the AMF. NYSE Euronext may decide not to repurchase any shares of its common stock or to discontinue the share repurchase program at any time.