Pricing strategy which calculates prices based on assumptions or financial models, as opposed to market values (which is what the mark-to-market strategy is based on). Mark to model is typically used when an asset doesn't have reliable market values for whatever reason. Because this method requires more speculation and guesswork, it also can be more risky, and contributed to the subprime mortgage crisis in the late 2000s. In late 2007, the FASB required that all public companies must disclose any assets that use mark to model valuation.