Accounting experts say the rebound in bank earnings in 2010-2011 is a good time to offset unrealized losses from troubled loans against higher earnings. These troubled assets make it hard to understand the true financial condition of banks, which becomes a major problem in financial crises. According to a WSJ analysis US banks had $13.8 billion in "unrealized losses" that have lasted at least a year in their portfolios as of Sept. 30, 2010. If these losses were taken now it would reduce bank's pretax income for the first 9 months of 2010 by 21%, according to the Journal analysis. Another problem focusses on Level 3 securities, which are illiquid investments that cannot easily be valued using market prices. The Journal analysis shows that as of Sept 30, 2011, the top ten banks had $360.7 billion in Level 3 securities. This is 42.6% of bank's shareholder's equity. At the top ten banks Level 3 securities fell by 24% in the last 2 years, which indicates an improvement. However some banks have made changes, whereas other large banks have not reduced the level of Level 3 securities. Take Bank of New York Mellon, for example, which took a $4.8 billion charge against earnings in 2009, largely related to mortgage backed securities. CEO Kelly said, it wanted to "put our investment securities issues behind us." Contrast that with Citigroup. Citgroup did not mention its high level of Level 3 securities when it anounced fourth quarter earnings. As of Sept 30, the bank held $79.1 billion of Level 3 securities- equal to 48% of its book value. This includes credit derivatives, asset backed securities and sub-prime mortgage securities....