QUESTIONS AND ANSWERS ABOUT THE MERGER, THE SPECIAL MEETING

AND THE VOTING MEETING

Coppermark’s shareholders will also transact such other business that may properly come before the special meeting. As of the date of this proxy statement/prospectus, Coppermark’s board of directors is not aware of any matters, other than those stated above, that may be brought before the special meeting.

At the special meeting of shareholders that will follow the voting meeting, all of the shares subject to the shareholders’ agreement will be voted for each item according to the outcome of the votes concerning that item at the voting meeting. Coppermark’s shareholders whose shares are subject to the shareholders’ agreement will also transact such other business that may properly come before the voting meeting. As of the date of this proxy statement/prospectus, the board of directors of Coppermark is not aware of any matters, other than those stated above, that may be brought before the voting meeting.

The merger consideration is subject to adjustment based on the ten (10) trading day average closing price of the Prosperity common stock in the manner and under the circumstances set forth in the reorganization agreement. The merger consideration is also subject to decrease in the event Coppermark Bank’s equity capital on the closing date of the merger is less than $122,577,000 in the manner and under the circumstances set forth in the reorganization agreement.

Item 1—FOR the approval of the reorganization agreement; and

Item 2—FOR the authority to adjourn or postpone the special meeting.

Item 1—FOR the approval of the reorganization agreement;

Item 2—FOR the authority to adjourn or postpone the voting meeting or the special meeting; and

Item 3—FOR termination of the shareholders’ agreement immediately before the merger is effective.

If your shares are subject to the shareholders’ agreement and holders of at least seventy percent (70%) of the shares subject to the shareholders’ agreement vote their shares in favor of the reorganization agreement at the voting meeting, you will not have the right to vote against approval of the reorganization agreement and dissent from the merger.

SUMMARY

This brief summary highlights selected information from this proxy statement/prospectus and may not contain all of the information that is important to you. We urge you to carefully read this entire document and the other documents we refer to in this document. These documents will give you a more complete description of the items for consideration at the special meeting and the voting meeting. For more information about Prosperity, see “Where You Can Find More Information” on page 91. We have included page references in this summary to direct you to other places in this proxy statement/prospectus where you can find a more complete description of the topics we have summarized.

The Companies

Prosperity Bancshares, Inc.

Prosperity, a Texas corporation, is a financial holding company pursuant to the Gramm-Leach-Bliley Act and bank holding company registered under the Bank Holding Company Act of 1956, as amended (the BHC Act). Through Prosperity Bank, its wholly owned subsidiary bank, Prosperity conducts a complete range of commercial and personal banking activities. Prosperity currently operates a total of two hundred thirteen (213) full-service banking centers, with fifty-nine (59) in the Houston area; twenty (20) in the South Texas area including Corpus Christi and Victoria; thirty-five (35) in the Dallas/Fort Worth area; twenty-one (21) in the East Texas area; thirty-four (34) in the Central Texas area including Austin and San Antonio; and ten (10) in the Bryan/College Station area. As of September 30, 2012, on a consolidated basis, Prosperity had total assets of $13.7 billion, total loans of $5.1 billion, total deposits of $11.0 billion and shareholders’ equity of $2.0 billion.

Coppermark Bancshares, Inc.

Coppermark Bancshares, Inc., an Oklahoma corporation, is a bank holding company registered under the BHC Act and the holding company for Coppermark Bank. Coppermark Bank, or CMB, currently has twelve (12) banking locations, six (6) full-service and three (3) limited-service locations in Oklahoma City, Oklahoma and surrounding areas and three (3) full-service locations in the Dallas, Texas area. As of September 30, 2012, on a consolidated basis, Coppermark had total assets of $1.3 billion, total deposits of $1.2 billion, total loans of $871.9 million and shareholders’ equity of $122.4 million.

Proposed Merger of Coppermark into Prosperity

We have attached the reorganization agreement to this document as Appendix A. Please read the entire reorganization agreement. It is the legal document that governs the merger.

We propose a merger whereby Coppermark will merge with and into Prosperity. Prosperity will be the surviving entity in the merger. Immediately following completion of the merger, CMB will merge into Prosperity Bank and all existing locations of CMB will become banking centers of Prosperity Bank. We expect to complete the merger during the late first quarter or early second quarter of 2013, although delays could occur.

Terms of the Merger of Coppermark into Prosperity (page 40)

Pursuant to the terms of the reorganization agreement, all outstanding shares of Coppermark common stock will be converted into an aggregate of 3,258,845 shares of Prosperity common stock and $60.0 million in cash, subject to adjustment. More specifically, if the average closing price of Prosperity’s common stock for the 10 consecutive trading days ending on and including the fifth trading day prior to the closing date of the merger, which we refer to herein as the average closing price, exceeds $49.40, the exchange ratio and/or the per share cash consideration will be decreased so that, as a result of such adjustment, the aggregate value of the merger consideration, based on the average closing price, equals no more than $220,987,000. In addition, if the average closing price of Prosperity’s common stock falls below $36.52 and Prosperity’s common stock underperforms the Powershares KBW Regional Banking Portfolio by more than fifteen percent (15%) during that same measurement period, Prosperity may increase the exchange ratio and/or the per share cash consideration so that, as a result of such adjustment, the total merger consideration, based on the average closing price, is not less than $179,013,000. The merger consideration is also subject to decrease in the event that Coppermark’s equity capital on the closing date of the merger is less than $122,577,000, in the manner and under the circumstances set forth in the reorganization agreement.

The market price of Prosperity common stock will fluctuate from the date of this proxy statement/ prospectus to the date of completion of the merger, and these fluctuations could result in an adjustment to the exchange ratio and/or the cash consideration. Because of the possibility of an adjustment to the exchange ratio and/or the cash consideration, you will not know the exact number of shares of Prosperity common stock or the exact amount of cash, you will receive in connection with the merger when you vote on the reorganization agreement.

Material U.S. Federal Income Tax Consequences (page 64)

The merger is intended to qualify as a reorganization under the Internal Revenue Code of 1986, as amended, or the Code. As a result of receiving Prosperity common stock and cash in exchange for Coppermark common stock, in general, shareholders of Coppermark will recognize gain, but not loss, equal to the lesser of cash received or gain realized in the merger. The amount of gain realized will equal the amount by which the cash plus the fair market value, at the effective time of the merger, of the Prosperity common stock exceeds the basis in the Coppermark common stock to be surrendered in exchange therefor.

This tax treatment may not apply to every shareholder of Coppermark. Determining the actual tax consequences of the merger to you may be complicated and will depend on your specific situation and on variables not within our control. You should consult your own tax advisor for a full understanding of the merger’s tax consequences to you.

Opinion of Financial Advisor of Coppermark (page 46)

Commerce Street Capital, LLC has delivered a written opinion to the board of directors of Coppermark that, as of the date of the reorganization agreement, based upon and subject to certain matters stated in the opinion, the merger consideration is fair to the holders of Coppermark common stock from a financial point of view. We have attached this opinion to this proxy statement/prospectus as Appendix B. The opinion of Commerce Street is not a recommendation to any Coppermark shareholder as to how to vote on the proposal to approve the reorganization agreement. You should read this opinion completely to understand the procedures followed, matters considered and limitations on the reviews undertaken by Commerce Street in providing its opinion.

Prosperity Plans to Continue to Pay Quarterly Dividends (page 86)

Following the merger, subject to applicable statutory and regulatory restrictions, Prosperity intends to continue its practice of paying quarterly cash dividends. For the fourth quarter of 2012, Prosperity paid a cash dividend of $0.215 per share.

Ownership of Prosperity After the Merger

Pursuant to the reorganization agreement, Prosperity will issue up to 3,258,845 shares of its common stock to Coppermark shareholders in connection with the merger. Based on [—] shares of Prosperity common stock outstanding as of [—], 2013, after the merger, the former Coppermark shareholders would own approximately [—]% of the outstanding shares of Prosperity common stock.

Market Prices of Prosperity Common Stock (page 86)

Shares of Prosperity common stock are quoted on the New York Stock Exchange under the symbol “PB.” On December 7, 2012, the last trading day before the merger was announced, Prosperity common stock closed at $41.23 per share. On [—], 2013, Prosperity common stock closed at $[—] per share. The market price of Prosperity common stock will fluctuate prior to the merger. You should obtain the current stock quotation for Prosperity common stock. Shares of Coppermark are not traded on any established public trading market.

The Coppermark Special Meeting (page 38)

The special meeting of shareholders of Coppermark will be held on [—], 2013, at [—] [—].m., local time, at [—], Oklahoma City, Oklahoma [—]. At the special meeting, you will be asked to consider and vote on the following:

Voting Meeting of Shareholders Subject to the Shareholders’ Agreement (page 38)

The voting meeting of the shareholders subject to the shareholders’ agreement will be held on [—], 2013, at [—] [—].m., local time (one hour before the special meeting), at [—], Oklahoma City, Oklahoma [—] (the same location as the special meeting) to provide direction as to how the Coppermark common stock subject to the shareholders’ agreement should be voted at the special meeting. At the voting meeting, these shareholders will be asked to consider and vote on the following:

Record Date Set at [—], 2013; Majority Shareholder Vote Required to Approve the Reorganization Agreement (page 39)

You may vote at the special meeting of Coppermark shareholders or the voting meeting, as applicable, if you owned Coppermark common stock at the close of business on [—], 2013 and on the date of the voting meeting, respectively. You can cast one vote for each share of Coppermark common stock you owned at that time. As of [—], 2013, there were [—] shares of Coppermark common stock outstanding.

Approval of the reorganization agreement requires the affirmative vote of the holders of a majority of the outstanding shares of Coppermark common stock entitled to vote. If you fail to vote, it will have the effect of a vote against the reorganization agreement. The affirmative vote of a majority of the shares of Coppermark common stock cast at the meeting is required to approve the postponement or adjournment of the meeting.

If your shares are not subject to the shareholders’ agreement, you may vote your shares of Coppermark common stock by attending the special meeting and voting in person or by completing and mailing the enclosed proxy card. If you are the record holder of your shares, you can revoke your proxy at any time before the vote is taken at the special meeting by sending a written notice revoking the proxy or a later-dated proxy to the Secretary of Coppermark, or by voting in person at the special meeting.

Voting of Shares Subject to the Shareholders’ Agreement (page 38)

You may vote at the voting meeting of Coppermark shareholders subject to the shareholders’ agreement if you owned Coppermark common stock subject to the shareholders’ agreement on the date of the voting meeting. You can cast one vote for each share of Coppermark common stock you owned at that time that was subject to the shareholders’ agreement. The list of shareholders and number of shares shown in the shareholders’ agreement attached as Appendix D was as of December 21, 2011 and does not reflect any transfers of Coppermark stock subject to the shareholders’ agreement made after such date. As such, you should not rely on such information. As of [—], 2013, there were [—] shares of Coppermark common stock subject to that agreement, which represents [—] of the total outstanding shares of Coppermark common stock.

All of the shares subject to the shareholders’ agreement will be voted at the special meeting FOR or AGAINST each proposal according to the result of the vote at the voting meeting pursuant to the terms of the shareholders’ agreement attached to this proxy statement/prospectus as Appendix D. Pursuant to the terms of the shareholders’ agreement, at least seventy percent (70%) of the shares subject to the shareholders’ agreement must be voted for approval of the reorganization agreement and to terminate the shareholders’ agreement at the voting meeting in order for any of the shares of Coppermark common stock subject to the shareholders’ agreement to be voted in favor of such proposal at the special meeting or for the shareholders’ agreement to be terminated, as applicable. The proposal to adjourn or postpone the voting meeting or the special meeting requires the affirmative approval of at least a majority (or [—] shares) of the outstanding shares of Coppermark common stock subject to the shareholders’ agreement and cast at the voting meeting.

If at least seventy percent (70%) of the shares subject to the shareholders’ agreement are voted in favor of approval of the reorganization agreement at the voting meeting, all of the shares subject to the shareholders’ agreement will be voted in favor of approval of the reorganization agreement at the special meeting. If you fail to vote at the voting meeting, it will have the effect at the voting meeting of a vote against the reorganization agreement. Because of the number of shares of Coppermark common stock subject to the shareholders’ agreement, the voting results at the voting meeting will determine the voting results at the special meeting.

If at least a majority of the shares subject to the shareholders’ agreement cast at the voting meeting are voted in favor of adjourning or postponing the voting meeting or the special meeting, then the voting meeting may be postponed or adjourned and all of the shares subject to the shareholders’ agreement may be voted in favor of postponing or adjourning the special meeting. If you fail to vote at the voting meeting, it will not have the effect at the voting meeting of a vote against postponing or adjourning these meetings.

If at least seventy percent (70%) of the shares subject to the shareholders’ agreement are voted in favor of termination of the shareholders’ agreement, then the shareholders’ agreement will terminate immediately before the merger is effective. If you fail to vote at the voting meeting, it will have the effect of a vote against termination of the shareholders’ agreement.

You may vote your shares of Coppermark common stock subject to the shareholders’ agreement by attending the voting meeting and voting in person or by completing and mailing the enclosed voting meeting proxy card. If you are the record holder of your shares, you can revoke your voting meeting proxy at any time before the vote is taken at the voting meeting by sending a written notice revoking the proxy or a later-dated proxy to Coppermark, or by voting in person at the voting meeting.

Coppermark’s Reasons for the Merger and Recommendations of Coppermark’s Board (page 44)

Based on the reasons discussed elsewhere in this proxy statement/prospectus, the board of directors of Coppermark believes that the merger is fair to you and in your best interests, and unanimously recommends that you vote FOR the proposal to approve the reorganization agreement. For a discussion of the circumstances surrounding the merger and the factors considered by the Coppermark’s board of directors in approving the reorganization agreement, see page 44.

Members of Coppermark’s Management are Expected to Vote Their Shares For Approval of the Reorganization Agreement (page 39; Exhibit A to Appendix A)

The directors and executive officers of Coppermark and CMB and holders of 10% or more of the outstanding Coppermark common stock have entered into an agreement to vote the shares of Coppermark common stock they control in favor of approval of the reorganization agreement. As of the record date, [—] shares of Coppermark common stock, or approximately [—]% of the outstanding shares of the common stock entitled to vote at the special meeting, were bound by the voting agreement. Of these shares, [—] are subject to the shareholders’ agreement and are eligible to vote at the voting meeting.

Effective Time of the Merger (page 54)

The merger will become effective at the date and time specified in the certificate of merger to be filed with the Texas Secretary of State and the certificate of merger and consolidation to be filed with the Oklahoma Secretary of State. If Coppermark shareholders approve the reorganization agreement at the special meeting, and if all necessary government approvals are obtained and the other conditions to the parties’ obligations to effect the merger are met or waived by the party entitled to do so, we anticipate that the merger will be completed in the late first quarter or early second quarter of 2013, although delays could occur.

We cannot assure you that the necessary shareholder and governmental approvals will be obtained or that the other conditions to completion of the merger can or will be satisfied.

Treatment of Coppermark Options (page 54)

Pursuant to the terms of the Coppermark Bancshares, Inc. Stock Option Plan and each underlying option agreement, each option to acquire Coppermark common stock will become exercisable upon the approval of the reorganization agreement by Coppermark’s shareholders at the special meeting. The board of directors of Coppermark will set a date prior to which all options may be exercised by the payment of cash by the holder of such option. After such date, all unexercised options will terminate.

Exchange of Coppermark Stock Certificates (page 53)

As soon as practicable after the effective time of the merger, you will receive a letter and instructions from Computershare Investor Services, acting in its role as Prosperity’s exchange agent, with respect to the procedures for surrendering your stock certificates representing shares of Coppermark common stock in exchange for stock certificates representing shares of Prosperity common stock and cash. You must carefully review and complete these materials and return them as instructed along with your stock certificates for Coppermark common stock. Please do not send Coppermark or Prosperity any stock certificates until you receive these instructions.

Conditions to Completion of the Merger (page 57)

The completion of the merger depends on a number of conditions being met. These include, among others:

Additionally, the completion of the merger depends on the execution of the following agreements, all of which have been executed, but will not become effective until the effective time of the merger:

Any condition to the completion of the merger may be waived in writing by the party to the reorganization agreement entitled to the benefit of such condition. A party to the reorganization agreement could choose to complete the merger even though a condition has not been satisfied, as long as permitted by law. We cannot be certain when or if the conditions to the merger will be satisfied or waived, or that the merger will be completed.

Regulatory Approvals Required (page 69)

We cannot complete the merger unless it is approved by the Board of Governors of the Federal Reserve System (Federal Reserve) or such approval is waived by the Federal Reserve. Prosperity intends to file any required documentation with the Federal Reserve Bank of Dallas to request a waiver of its approval after the regulatory applications required for the bank merger (as described below) are accepted for filing.

In addition, the merger of CMB with and into Prosperity Bank requires the approval of the Federal Deposit Insurance Corporation (FDIC) and the Texas Department of Banking (TDB). We expect to obtain all necessary regulatory approvals, although we cannot be certain if or when we will obtain them. On January 7, 2013, Prosperity Bank and CMB filed applications with the FDIC and the TDB to obtain approval of the bank merger. The U.S. Department of Justice will have between 15 and 30 days following approval by the FDIC to challenge the approval on antitrust grounds. While Coppermark and Prosperity do not know of any reason that the Department of Justice would challenge regulatory approval by the FDIC and believe that the likelihood of such action is remote, there can be no assurance that the Department of Justice will not initiate such a proceeding, or if such a proceeding is initiated, as to the result of any such challenge.

Amendments or Waiver (page 62)

Prosperity and Coppermark may amend the reorganization agreement and each party may waive its right to require the other party to adhere to any term or condition of the reorganization agreement. However, the merger consideration to be received by the shareholders of Coppermark pursuant to the terms of the reorganization agreement may not be decreased after the approval of the reorganization agreement without the further approval of the Coppermark shareholders.

Termination of the Reorganization Agreement (page 62)

Prosperity and Coppermark can mutually agree at any time to terminate the reorganization agreement without completing the merger. In addition, either Prosperity or Coppermark may decide, without the consent of the other, to terminate the reorganization agreement if:

Coppermark may terminate the reorganization agreement, without the consent of Prosperity, if:

In addition, Prosperity may terminate the reorganization agreement, without the consent of Coppermark, if any required regulatory approval is obtained subject to restrictions or conditions on the operations of Coppermark, CMB, Prosperity or Prosperity Bank that are reasonably unacceptable to Prosperity.

Prosperity also has the right to terminate the reorganization agreement on or prior to March 10, 2013, if the results of any environmental inspections or surveys of Coppermark properties identify certain potential or current violations of environmental laws or environmental law requires certain remedial or clean up action that could have a material adverse effect on Coppermark.

Termination Fee (page 63)

If the reorganization agreement is terminated by:

then Coppermark will be required to pay Prosperity a termination fee of $8.5 million.

If either Prosperity or Coppermark terminates the reorganization agreement after June 8, 2013 (or July 8, 2013, if regulatory approval has not been obtained by June 8, 2013) and Coppermark’s shareholders have not approved the reorganization agreement by such date, or, without regard to timing, if Coppermark’s shareholders do not approve the reorganization agreement and an acquisition proposal exists at the time of termination, Coppermark will be required to pay Prosperity up to $500,000 for its expenses related to the proposed transaction.

If Prosperity or Coppermark terminates the reorganization agreement because Coppermark’s shareholders fail to approve the reorganization agreement and, within twelve (12) months of termination of the reorganization agreement, Coppermark enters into an acquisition agreement with a third party, Coppermark will be required to pay Prosperity a termination fee of $8.5 million, in addition to the $500,000 for its expenses related to the proposed transaction previously paid.

Some of the Directors and Officers of Coppermark Have Financial Interests in the Merger that Differ from Your Interests (page 61)

Some of the directors and officers of Coppermark have interests in the merger that differ from, or are in addition to, their interests as shareholders of Coppermark. These interests include:

Comparison of Rights of Shareholders of Coppermark and Prosperity (page 72)

Coppermark is an Oklahoma corporation and the rights of shareholders of Coppermark are governed by Oklahoma law and Coppermark’s certificate of incorporation and bylaws. Prosperity is a Texas corporation and the rights of Prosperity shareholders are governed by Texas law and Prosperity’s articles of incorporation and bylaws. Upon completion of the merger, shareholders of Coppermark will become shareholders of Prosperity and their rights will be governed by Prosperity’s articles of incorporation and bylaws, in addition to Texas law. Prosperity’s articles of incorporation and bylaws will remain the same unless later altered, amended or repealed.

Dissenters’ Rights of Appraisal in the Merger (page 69)

A shareholder of Coppermark whose shares are not subject to the shareholders’ agreement has the right under Oklahoma law to dissent from the merger and have the appraised fair value of his shares of Coppermark common stock paid to him in cash. The appraised fair value may be more or less than the value of the shares of Prosperity common stock and cash being paid in the merger.

If your shares are subject to the shareholders’ agreement and at least seventy percent (70%) of the shares subject to the shareholders’ agreement vote their shares in favor of the reorganization agreement at the voting meeting, you will not have the right to vote against approval of the reorganization agreement and dissent from the merger.

Persons having beneficial interests in Coppermark common stock held of record in the name of another person, such as a broker or bank, must act promptly to cause the record holder to take the actions required under Oklahoma law to exercise your dissenter’s rights.

In order to dissent, you must carefully follow the requirements of the Oklahoma General Corporation Act, including giving the required written notice prior to the special meeting at which the vote on the reorganization agreement is taken. These steps are summarized under the caption “—Dissenters’ Rights of Coppermark Shareholders” on page 69.

If you intend to exercise dissenters’ rights, you should read the statutes carefully and consult with your own legal counsel. You should also remember that if you return a signed proxy card, but fail to provide instructions as to how your shares of Coppermark common stock are to be voted, you will be considered to have voted in favor of the reorganization agreement and you will not be able to assert dissenters’ rights. Furthermore, if your shares are subject to the shareholders’ agreement and you vote your shares at the voting meeting against approval of the reorganization agreement, but the requisite number of shares subject to the shareholders’ agreement are voted in favor of approval of the reorganization agreement such that such shares are voted at the special meeting to approve the reorganization agreement, you will be considered to have voted in favor of the reorganization agreement and you will not be able to assert dissenters’ rights.

Also, if you exercise dissenters’ rights, you may have taxable income as a result, so you should consult with your own tax advisor if you intend to dissent. See “—Material U.S. Federal Income Tax Consequences of the Merger.” If the reorganization agreement is approved by the shareholders of Coppermark, holders of Coppermark common stock who deliver to Coppermark a written demand for appraisal of their shares before the Coppermark special meeting, do not vote in favor of the reorganization agreement and merger and continue to hold their shares of Coppermark common stock through the effective time of the merger will be entitled to receive the appraised fair value of their shares, and accrued interest, in cash under the Oklahoma General Corporation Act.

The text of the provisions of the Oklahoma General Corporation Act pertaining to dissenters’ rights is attached to this proxy statement/prospectus as Appendix C.

Recent Developments

Recently Completed Acquisition

East Texas Financial Services, Inc. Prosperity completed the acquisition of East Texas Financial Services, Inc. (“ETFS”) and its wholly-owned subsidiary, First Federal Bank Texas, on January 1, 2013. Pursuant to the terms of the agreement, Prosperity issued 530,940 shares of Prosperity common stock for all of the outstanding shares of ETFS common stock. First Federal Bank Texas operated three (3) locations in Tyler, Texas, and one (1) location in Gilmer, Texas. Prosperity currently operates twenty-seven (27) banking centers in the East Texas area. As of December 31, 2012, ETFS reported total assets of $165.0 million, total loans of $129.3 million and total deposits of $112.3 million.

Unaudited Preliminary Financial Results of Prosperity for the Year Ended December 31, 2012

Prosperity is currently in the process of finalizing its financial results for the year ended December 31, 2012. On January 25, 2013, Prosperity announced unaudited preliminary results for the year ended December 31, 2012. Net income for the year was $167.9 million or $3.23 per diluted common share, an increase of 18.4% compared with net income of $141.7 million for the previous year and an increase of 7.3% compared with diluted earnings per common share of $3.01 for the previous year. For the year ended December 31, 2012, Prosperity’s return on average assets was 1.35% and its return on average common equity was 9.10%. For the year ended December 31, 2012, Prosperity’s net interest income before the provision for loan losses was $380.7 million compared with $326.7 million during the same period in 2011, an increase of 16.5%. The increase was attributable primarily to an increase in earning assets. Prosperity’s net interest margin on a tax-equivalent basis was 3.53% for the year ended December 31, 2012, compared with 3.98% for the same period in 2011.

At December 31, 2012, Prosperity had total assets of $14.6 billion, total loans of $5.2 billion, total deposits of $11.6 billion and total shareholders’ equity of $2.1 billion. Prosperity’s nonperforming assets totaled $13.0 million, or 0.12% of average earning assets, at December 31, 2012 compared with $12.1 million, or 0.15% of average earning assets, at December 31, 2011. The allowance for credit losses was $52.6 million, or 1.01% of total loans, at December 31, 2012 compared with $51.6 million, or 1.37% of total loans, at December 31, 2011.

The following table presents Prosperity’s selected consolidated financial data as of and for the year ended December 31, 2012 and 2011. The preliminary financial data for 2012 set forth below is unaudited and should be read in conjunction with Prosperity’s consolidated financial statements and notes to the consolidated financial statements contained in reports that Prosperity has previously filed with the Securities and Exchange Commission. See “Where You Can Find More Information” on page 91.

The preliminary financial data for the year ended December 31, 2012 included in this proxy statement/prospectus has been prepared by management of Prosperity. The process for finalizing the year end results is not yet complete, and more complete financial statements are not expected to be available until a number of weeks after the date of this proxy statement/prospectus. The preliminary financial data presented are therefore preliminary estimates and are subject to change. Actual results could differ materially as Prosperity finalizes such results.

Unaudited Preliminary Financial Results of Coppermark for the Year Ended December 31, 2012

The net income of Coppermark for the year ended December 31, 2012 was $15.9 million, or $2.76 per basic and $2.74 per diluted common share, compared with net income of $14.6 million, or $2.57 per basic and $2.52 per diluted common share, for the previous year, an increase of $1.3 million or 8.7%. The increase was primarily due to a reduction in provision expense as well as a decrease in net noninterest expense. For the year ended December 31, 2012, Coppermark’s return on average assets was 1.23% and its return on average equity was 13.21%. For the year ended December 31, 2012, Coppermark’s net interest income before the provision for possible credit losses was $43.9 million compared with $45.4 million for the previous year, a decrease of 3.2%. The decrease was attributable primarily to reduced interest income on loans. Coppermark’s net interest margin was 3.63% for the year ended December 31, 2012, compared with 3.88% for the same period in 2011.

At December 31, 2012, Coppermark had total assets of $1.3 billion, total loans of $853.4 million, total deposits of $1.2 billion and total shareholders’ equity of $128.1 million. Coppermark’s nonperforming assets totaled $1.1 million, or 0.08% of total assets, at December 31, 2012, compared with $8.0 million, or 0.63% of total assets, at December 31, 2011. The allowance for possible credit losses was $11.2 million, or 1.31% of total loans, at December 31, 2012 compared with $12.9 million, or 1.41% of total loans, at December 31, 2011.

The following table presents Coppermark’s selected financial data as of and for the year ended December 31, 2012 and 2011.

Selected Historical Consolidated Financial Data of Prosperity

The following table summarizes financial results actually achieved by Prosperity for the periods and as of the dates indicated and should be read in conjunction with Prosperity’s consolidated financial statements and the notes to the consolidated financial statements contained in reports that Prosperity has previously filed with the SEC. Historical financial information for Prosperity can be found in its Annual Report on Form 10-K for the year ended December 31, 2011. See “Where You Can Find More Information” on page 91 for instructions on how to obtain the information that has been incorporated by reference. Financial amounts as of and for the nine months ended September 30, 2012 and 2011 are derived from Prosperity’s unaudited interim consolidated financial statements, which Prosperity’s management believes reflect all adjustments (consisting only of normal recurring adjustments) necessary for a fair presentation of its results of operations and financial position as of the dates and for the periods indicated. You should not assume the results of operations for past periods and for any interim period indicate results for any future period.