definiens: means the amount whic h a willing buyer would pay a willing seller in an arm 's length transaction, assu ming each party acts with full knowledge of the facts and without undue press ure or compulsion to complete such transaction as determined by mutual agreement of the parties hereto in good faith . For purposes of calculating Fair Market Valu e, the value of any securities ( whether debt or equity ) that are freely tradable in an established public market will be determined on the basis of th e average closing price in such market during the ten business days prior to t he date upon which the determination is to be made ( the ), and the value of securities that are not freely tradable ( or have no established public market ) or other property will be the fair market value of such securities or other property upon receipt by DIVERSA as determined in g ood faith and upon mutual agreement of XOMA and DIVERSA or, if agreement cann ot be reached, as calculated by a nationally recognized investment bank retained by XOMA, and reasonably acceptable to DIVERSA, and whose fees shall be shar ed equally by the parties