Citigroup’s credit write-downs surrounding the subprime crisis amounted to over $4 billion dollars with $1 billion related to write-downs of mortgage backed securities.  The pessimistic view of US mortgage environment also led to an increase in mortgage lending costs of $2.4 billion.  The markets ended up cheering on the numbers, probably as a sigh of relief that a bank has come out an opened up to its losses surrounding the subprime problems.