Wall Street is bracing itself this week for news of large losses, multibillion dollar writedowns and thousands of job cuts as Citigroup and Merrill Lynch, two of the biggest casualties of the credit crunch, report results. Citi is likely to report a writedown of more than $10bn and Merrill, more than $7bn, say analysts. Investors fear this could reverse the slight improvement in sentiment in recent weeks. JPMorgan Chase, which has fared better than many rivals, also reports this week. Analysts expect a near-halving in profits from the previous year.