Revenue Recognition Investment advisory and services fees, generally calculated as a percentage of AUM, are recorded as revenue as the related services are performed. Certain investment advisory contracts, including those associated with hedge funds or other alternative investments, provide for a performance-based fee, in addition to a base advisory fee, which is calculated as either a percentage of absolute investment results or a percentage of investment results in excess of a stated benchmark over a specified period of time. Performance-based fees are recorded as a component of revenue at the end of each contract's measurement period. We calculate AUM using established fair valuation methodologies, including market-based valuation methods and fair valuation methods. Market-based valuation methods include: last sale/settle prices from an exchange for actively-traded listed equities, options and futures; evaluated bid prices from recognized pricing vendors for fixed income, asset-backed or mortgage-backed issues; mid prices from recognized pricing vendors and brokers for credit default swaps; and quoted bids or spreads from pricing vendors and brokers for other derivative products. Fair valuation methods include discounted cash flow models, evaluation of assets versus liabilities or any other methodology that is validated and approved by our Valuation Committee. Fair valuation methods are used only where AUM cannot be valued using market-based valuation methods, such as in the case of private equity or illiquid securities. Investments utilizing fair valuation methods typically make up an insignificant amount of our total AUM. Recent market volatility has not had a significant effect on our ability to acquire market data and, accordingly, our ability to use market-based valuation methods. The Valuation Committee, which is composed of senior officers and employees, is responsible for overseeing the pricing and valuation of all investments held in client and AllianceBernstein portfolios. The Valuation Committee has