Citigroup kicked off earnings season Monday with quarterly profit and revenue that rose and beat Wall Street's expectations.
Strength in consumer banking offset weakness in its trading business.
Consumers continued to borrow money, boosting Citi's loans and deposits.
Trading revenue, however, shrank in both fixed-income and equities.
Bank executives had been warning that slower activity among clients and Brexit-related uncertainties would hit trading revenue.
Citigroup shares fell slightly and pulled down other bank shares.
Citi's net interest margins got squeezed, and that had investors worried that this would lead to lower earnings and profitability for big U.S. banks.
Net interest margin is the difference between what banks pay on their deposits and what they make on their loans.
Investors will get results from JPMorgan Chase and Wells Fargo on Tuesday and Bank of America on Wednesday.