Mark-to-market accounting
Mark-to-market (MTM or M2M) or fair value accounting is accounting for the "fair value" of an asset or liability based on the current market price, or the price for similar assets and liabilities, or based on another objectively assessed "fair" value. Fair value accounting has been a part of Generally Accepted Accounting Principles (GAAP) in the United States since the early 1990s.
Source: Wikipedia — Mark-to-market accounting (CC BY-SA 4.0)