SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549


                                    FORM 8-K


                             Current Report Pursuant
                          to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934


         Date of Report (Date of earliest event Reported): March 2, 2000


                                   ARIBA, INC.
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             (Exact Name of Registrant as Specified in its Charter)


         Delaware                      7372                  77-0439730
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(State or Other Jurisdiction     (Commission File         (I.R.S. Employer
    of Incorporation)                 Number)           Identification Number)


                              1565 Charleston Road
                         Mountain View, California 94043
                                 (650) 930-6200
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 (Addresses, including zip code, and telephone numbers, including area code, of
                          principal executive offices)



ITEM 2.  ACQUISITION OR DISPOSITION OF ASSETS

         On March 8, 2000, Ariba, Inc., a Delaware corporation ("Ariba"), and
Tradex Technologies, Inc., a Delaware corporation ("Tradex"), consummated a
merger (the "Merger") whereby Apache Merger Corporation, a Delaware corporation
and a wholly-owned subsidiary of Ariba ("Merger Sub"), was merged with and into
Tradex pursuant to an Agreement and Plan of Reorganization (the "Merger
Agreement") dated as of December 16, 1999, as amended. Tradex has survived the
merger as a wholly-owned subsidiary of Ariba.

         Pursuant to the Merger Agreement, each issued and outstanding share of
common stock of Tradex ("Tradex Common Stock") was converted into the right to
receive .68356 shares of common stock of Ariba ("Ariba Common Stock"). In
addition, each option to purchase Tradex Common Stock outstanding at the time of
the Merger under the Tradex's stock option plans was converted into an option to
purchase the number of shares of Ariba Common Stock equal to the number of
shares of common stock of Tradex subject to such option multiplied by the
exchange ratio for the Merger, and the associated exercise price was adjusted
accordingly.

ITEM 5.  OTHER EVENTS.

         On March 2, 2000, the board of directors of Ariba authorized a
two-for-one stock split to be effected in the form of a stock dividend. The
stock split will be effected by distribution to each stockholder of record as
of March 20, 2000 of one share of Ariba's common stock for each share of
common stock then held. Ariba expects the shares resulting from the split to
be distributed by Ariba's transfer agent on or about March 31, 2000. The
stock split will



increase the number of shares of Ariba common stock outstanding from
approximately 96,828,000 million shares as of March 2, 2000 to approximately
193,656,000 million shares.

ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.

         (a) FINANCIAL STATEMENTS.

         The Registrant will provide the financial statements required by
paragraph (a) of Item 7 of Form 8-K promulgated by the Securities and Exchange
Commission (the "Commission") pursuant to the Securities Exchange Act of 1934,
as amended (the "Exchange Act"), if any such information is required, on a Form
8-K/A within 60 days of the date that this initial report on Form 8-K is
required to be filed with the Commission.

         (b) PRO FORMA FINANCIAL INFORMATION.

         The Registrant will provide the pro forma financial information
required by paragraph (b) of Item 7 of Form 8-K promulgated by the Commission
pursuant to the Exchange Act, if any such pro forma financial information is
required, on a Form 8-K/A within 60 days of the date that this initial report on
Form 8-K is required to be filed with the Commission.

         (c)      EXHIBITS.

                  2.1      Agreement and Plan of Reorganization, dated as of
                           December 16, 1999, among Ariba, Inc., Apache Merger
                           Corporation and Tradex Technologies, Inc.

                  2.2      Amendment No. 1 to Agreement and Plan of
                           Reorganization, dated as of January 24, 2000, among
                           Ariba, Inc., Apache Merger Corporation and Tradex
                           Technologies, Inc.

                  99.1     Text of press release dated March 10, 2000.

                  99.2     Text of press release dated March 2, 2000.



                                   SIGNATURES


         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.


                                          ARIBA, INC.


DATE:  March 21, 2000                     By:  /s/ Edward P. Kinsey
                                               -------------------------------
                                               Edward P. Kinsey
                                               Chief Financial Officer,
                                               Executive Vice-President-Finance
                                               and Administration and Secretary
                                               (Principal Financial and
                                               Accounting Officer)



                                INDEX TO EXHIBITS


       Exhibit                     Description
       -------                     -----------

         2.1      Agreement and Plan of Reorganization dated as of December 16,
                  1999 among Ariba, Inc., Apache Merger Corporation and Tradex
                  Technologies, Inc.

         2.2      Amendment No. 1 to Agreement and Plan of Reorganization, dated
                  as of January 24, 2000, among Ariba, Inc., Apache Merger
                  Corporation and Tradex Technologies, Inc.

         99.1     Text of Press Release dated March 10, 2000

         99.2     Text of Press Release dated March 2, 2000