Citigroup set aside a $322 million reserve for mortgage repurchases, the bank said in its quarterly earnings. That brings the total amount of reserves up to $952 million. Last week, investors sold off bank stocks after chatter began to spread about repurchase risk being much higher than expected. The idea is that banks may have to repurchase mortgage loans sold to investors as securities, perhaps because mortgage pools didn’t live up to the representations and warranties made in the sales materials.