This excerpt taken from the NDAQ 8-K filed Jan 27, 2006.
Earnings (Loss) Per Share
Basic earnings (loss) per share (EPS) is calculated by dividing net earnings by the weighted average number of common shares outstanding. Common shares outstanding include common stock for which no future service is required as a condition to the delivery of the underlying common stock. Diluted EPS includes the determinants of basic EPS and, in addition, reflects the dilutive effect of the common stock deliverable pursuant to stock options and to restricted stock for which future service is required as a condition to the delivery of the underlying common stock. The dilutive effect is included in the calculation of weighted average shares for the year ended that the Company has net income. Accordingly, in years that reflect a net loss the diluted EPS computation does not include the anti-dilutive effect of these options.
For the years ended December 31, 2003 and 2002, EPS computations do not include the anti-dilutive effect of stock options of 1,355 and 593 shares.