This excerpt taken from the AAPL 10-Q filed May 4, 2005.
Fair Market Value means, as of any date, the value of Common Stock determined as follows:
(i) If the Common Stock is listed on any established stock exchange or a national market system, including without limitation the Nasdaq National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its Fair Market Value shall be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such exchange or system, on the date of determination or, if the date of determination is not a trading day, the immediately preceding trading day;
(ii) If the Common Stock is regularly quoted by a recognized securities dealer but selling prices are not reported, the Fair Market Value of a Share of Common Stock shall be the mean between the high bid and low asked prices for the Common Stock on the date of determination or, if there are no quoted prices on the date of determination, on the last day on which there are quoted prices prior to the date of determination; or
(iii) In the absence of an established market for the Common Stock, the Fair Market Value shall be determined in good faith by the Administrator.