Credit Suisse saw more than $200 million net outflows from its U.S. and European managed funds after March 13, Morningstar Direct said on Friday.
DBRS Morningstar on Thursday became the first global rating agency to cut the bank's credit score, with a downgrade to "BBB", which still qualifies Credit Suisse as investment grade.
Credit Suisse shares are down about 26% this week and poised for their biggest week drop since October 2008 and the global financial crisis.
U.S. shareholders of Credit Suisse sued the bank on Thursday, claiming it defrauded them by concealing problems with its finances.
Credit Suisse declined to comment on the lawsuit.