This excerpt taken from the NDAQ 8-K filed Feb 20, 2008.
OMXs goodwill is tested annually for impairment. The value in use of goodwill attributable to exchange operations is calculated based on the discounted external cash flow which has been applied against the background of OMXs long history of a stable and strong cash flow.
OMXs intangible assets, e.g., software, customer contracts and development projects, are assessed for impairment in value whenever events or changes in conditions indicate that the carrying amount may not be recoverable. The review of the value of all intangible assets takes place on an ongoing basis throughout the year by using a risk-adjusted discounted cash flow analysis. The estimated useful lives of these intangible assets are assessed on an ongoing basis.
These reviews are based on assumptions and estimates (such as future cash-flow, useful life and discount factor) which entail a certain degree of uncertainty. If the actual outcome deviates from these assumptions and estimates, it will have a material impact on the financial statements.