what are mark to market losses 
mark to market losses are paper losses generated through an accounting entry rather than the actual sale of a security mark to market losses occur when financial instruments held are valued at the current market value which is lower than the price paid to acquire them the bottom linecertain assets and liabilities that fluctuate in value over time need to be periodically appraised based on current market conditions that includes certain accounts on a company s balance sheet and futures contracts mark to market essentially shows how much the item in question would receive if it were to be sold today and is an alternative to historical cost accounting which maintains an asset s value at the original purchase cost having an accurate up to date idea of what assets are worth serves many useful purposes however it can also be flawed for example during periods of economic turmoil market based measurements may not accurately reflect the underlying asset s true value 