UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

Bank One Corporation

Registrant’s telephone number, including area code: (312) 732-4000

Item 5. Other Events

J.P. Morgan Chase & Co., a Delaware corporation (“JPMorgan Chase”), and Bank One Corporation, a Delaware corporation (“Bank One”), have entered into an Agreement and Plan of Merger, dated as of January 14, 2004 (the “Merger Agreement”). The Merger Agreement provides for the merger of Bank One with and into JPMorgan Chase (the “Merger”). The Merger will be treated as a purchase business combination by JPMorgan Chase under U.S. generally accepted accounting principles. Completion of the Merger is subject to various conditions, including the receipt of all required regulatory approvals and the approval of the Merger by the stockholders of both JPMorgan Chase and Bank One.

Upon completion of the Merger, which is expected to occur in mid-2004, each share of common stock of Bank One, $0.01 par value per share, outstanding immediately prior to the effective time of the Merger, will be converted into 1.32 shares of JPMorgan Chase common stock, $1.00 par value per share.

PRELIMINARY UNAUDITED PRO FORMA
COMBINED FINANCIAL DATA

The following preliminary unaudited pro forma combined financial information and explanatory notes present how the combined financial statements of JPMorgan Chase and Bank One may have appeared had the businesses actually been combined. The preliminary unaudited pro forma combined financial information shows the impact of the Merger of JPMorgan Chase and Bank One on the combined companies’ financial positions and results of operations under the purchase method of accounting with JPMorgan Chase treated as the acquirer. Under this method of accounting, JPMorgan Chase will record the assets and liabilities of Bank One at their estimated fair values as of the date the Merger is completed. The preliminary unaudited pro forma combined balance sheet at September 30, 2003, assumes the Merger was completed on that date. The preliminary unaudited pro forma combined statements of income for the nine months ended September 30, 2003, and for the year ended December 31, 2002, give effect to the Merger as if the Merger had been completed on January 1, 2002. The financial information herein does not reflect any assumptions related to the stock repurchase program that has recently been announced.

The preliminary unaudited pro forma combined financial information has been derived from and should be read in conjunction with the historical consolidated financial statements and the related notes of both JPMorgan Chase and Bank One.

The preliminary unaudited pro forma combined financial information is presented for illustrative purposes only and does not indicate the financial results of the combined companies had the companies actually been combined at the beginning of each period presented and had the impact of possible revenue enhancements, expense efficiencies, asset dispositions and share repurchases, among other factors, been considered. In addition, as explained in more detail in the accompanying notes to the preliminary unaudited pro forma combined financial information, the allocation of the purchase price reflected in the preliminary unaudited pro forma combined financial information is subject to adjustment and will vary from the actual purchase price allocation that will be recorded upon completion of the Merger based upon changes in the balance sheet and changes in fair value.

JPMorgan Chase/Bank One
Pro Forma Combined Unaudited Statement of Income
For the Nine Months Ended September 30, 2003
(in millions, except share and per share data)

The Notes to pro forma combined financial information are an integral part of these statements.

JPMorgan Chase/Bank One
Pro Forma Combined Unaudited Statement of Income
For the Year Ended December 31, 2002
(in millions, except shares and per share data)

The Notes to pro forma combined financial information are an integral part of these statements.

JPMorgan Chase/Bank One
Pro Forma Combined Unaudited Balance Sheet
September 30, 2003
(in millions)

The Notes to pro forma combined financial information are an integral part of these statements.

Notes to Unaudited Pro Forma Combined Financial Information

Note 1 — Basis of Pro Forma Presentation

The preliminary unaudited pro forma combined financial information relating to the Merger is presented as of and for the nine months ended September 30, 2003 and for the year ended December 31, 2002. The Reporting Reclassification column represents the change in presentation of certain amounts on the historical consolidated financial statements of Bank One and JPMorgan Chase to conform with the preliminary presentation for the combined entity. For purposes of identifying the reclassification between line items on the financial statements, numerical references are provided to reflect where certain balances have been reclassified. Final determination of financial statement presentation will be completed upon consummation of the Merger. During the fourth quarter of 2003, Bank One sold its corporate trust services business to JPMorgan Chase and reported it as discontinued operations. For purposes of the accompanying pro forma financial information, Bank One’s income from discontinued operations has been reclassified to income from continuing operations to reflect the retention of this business in the combined entity.

JPMorgan Chase and Bank One are in the process of reviewing their accounting policies and, as a result of this review, it may be necessary to reclassify either JPMorgan Chase’s or Bank One’s financial statements to conform to those accounting policies that are determined by the combined company to be most appropriate. While some reclassifications of prior periods have been included in the pro forma combined financial information included in this document, most notably the adoption of FASB Interpretation No. 46 by Bank One as of the date of adoption by JPMorgan Chase, as further described below, further reclassifications may be necessary upon the completion of this review.

Material intercompany transactions have been eliminated from the accompanying preliminary unaudited pro forma combined financial information. However the information does not reflect the elimination of hedge accounting results and positions for certain intercompany derivatives. Management believes this presentation is more reflective of the pro forma results of the combined entity as such derivatives qualified for hedge accounting in the periods presented and will continue to qualify as hedges until the date the Merger is completed and it is management's intent to continue hedging with third parties subsequent to closing.

The pro forma adjustments include purchase price adjustments based on the conversion of Bank One common stock into JPMorgan Chase common stock using an exchange ratio of 1.32 applied to 1,117,924,000 shares of Bank One common stock outstanding at September 30, 2003 multiplied by the average share price of $39.02 per share of JPMorgan Chase common stock. The share price was computed using the average closing price of JPMorgan Chase common stock for the period commencing two trading days prior to and ending two trading days after the Merger was announced on January 14, 2004. Also included in the purchase price is the estimated value of $671 million representing 52.5 million vested employee stock options of Bank One that will be converted into options on JPMorgan Chase common stock upon consummation of the Merger. The total estimated purchase price for purposes of this pro forma financial information is $58.251 billion.

The Merger will be accounted for using the purchase method of accounting requiring the assets (including identified intangible assets and goodwill) and liabilities of Bank One to be fair-valued as of the date of acquisition.

The preliminary unaudited pro forma combined financial information includes estimated adjustments to record the assets and liabilities of Bank One at their respective fair values and represents management’s best estimates based on information available at this time. The pro forma adjustments may be revised as additional information becomes available and additional analysis is performed. The final allocation of the purchase price will be determined after the Merger is completed and after completion of a final analysis to determine the fair values of Bank One’s tangible and identifiable intangible assets and liabilities as of the closing date. The final purchase accounting adjustments may be materially different from the pro forma adjustments presented in this document. Increases or decreases in the fair value of certain balance sheet amounts including loans, credit card and related intangible assets, securities, deposits and debt will result in adjustments to the balance sheet and/or income statement. Such adjustments compared to the information shown in this document may change the amount of the purchase price allocated to goodwill and other assets and liabilities and may impact the statement of income due to adjustments in yield and/or amortization of the adjusted assets or liabilities.

The preliminary unaudited pro forma combined financial information presented in this document does not necessarily indicate the results of operations or the combined financial position that would have resulted had the Merger been completed at the beginning of the applicable period presented, nor is it indicative of the results of operations in future periods or the future financial position of the combined company.

The Merger is expected to result in cost savings of approximately $2.2 billion (pre-tax) and be achieved over a three-year period. These savings have not been included in the pro forma combined amounts.

It is anticipated that the Merger will result in restructuring and merger-related costs of approximately $3.0 billion, pre-tax. Under current accounting rules, a portion of these costs will not be accruable at the effective time of the Merger. The detailed plans for the restructuring initiatives have not been finalized and, as such, the amount of restructuring costs accruable at the effective time of the Merger has not been determined. The anticipated restructuring costs have not been reflected in the pro forma combined balance sheet and pro forma combined statement of income.

Note 2 — Reporting Reclassifications

Statements of Income

Balance Sheet

Note 3 — Pro Forma Adjustments

The preliminary unaudited pro forma combined financial information reflects the issuance of 1,475,660,000 shares of JPMorgan Chase common stock with an aggregate value of $57.580 billion and the conversion of approximately 52.5 million Bank One employee stock options with a value of $671 million at September 30, 2003. The fair value of JPMorgan Chase options that will be issued in exchange for the Bank One options was estimated using a Black-Scholes option pricing model. Option pricing models require the use of highly subjective assumptions including expected stock price and volatility that, when changed, can materially affect fair value estimates. The more significant assumptions used in estimating the fair value of the JPMorgan Chase stock options to be issued in the exchange for the Bank One stock options include a risk-free interest rate of 3.62%, a dividend yield of 3.409%, a weighted average expected life of 6.8 years and volatility of 41.38%. The 6.8 year term was based on the weighted average expected term to expiration of these options.

The pro forma adjustments included in the preliminary unaudited pro forma combined financial information are as follows:

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: February 3, 2004