Operating expenses declined 1 percent, surprising analysts and indicating that the company was on the way to meeting financial targets for this year.
The company also showed an improvement in the yield from its North America Citi-branded card business, which analysts were watching closely, adding another argument for its profit outlook.
Citigroup's shares rose 1.6 percent to $69.48.
Investors have been waiting to see how trading revenue fared at the five big Wall Street banks, due to an escalating U.S-China trade war and executives warning that the business's growth would be muted.
Citigroup reported a 9-percent jump in bond trading revenue, outperforming bigger rival JPMorgan Chase & Co, which reported a 10 percent drop in fixed-income trading revenue.
Chief Financial Officer John Gerspach had previously said Citigroup expected total fixed income and equity trading revenue to be "flat to slightly higher" in the third quarter.
In a conference call with reporters, Gerspach said that the expense savings showed that the company is improving its efficiency as executives had projected.
Citigroup is in the midst of a drive to save $2.8 billion in costs by 2020 as it spends $1.5 billion on technology and other productivity improvements.
Citigroup reported a 2-percent rise in global consumer banking revenue. The bank recently restructured its U.S. consumer business to operate more like those in Asia and Mexico, where it has been seeing better results.
Consumer banking revenue in Latin America rose 8 percent, excluding a one-time gain and on a constant-currency basis.
Yields from the North America branded card business turned up as more promotional credit card loans, which charge no interest for as long as 21 months, converted to interest-earning.
Gerspach said the promotional strategy was paying off as interest-earning balances grew 7 percent and net interest revenue as a percent of loans in a core portfolio rose to was 8.51 percent from 8.28 percent in the second quarter.
"That is a good indicator of the future for this business," Gerspach said.
Net income for the third-largest U.S. bank by assets rose to $4.62 billion in the third quarter ended Sept. 30, from $4.13 billion a year earlier.
Earnings per share rose to $1.73 from $1.42, helped by buybacks that reduced shares outstanding by 8 percent from a year earlier.
Analysts on average had expected earnings per share of $1.69, according to I/B/E/S data from Refinitiv. Total revenue was slightly lower at $18.39 billion, from $18.42 billion a year earlier.
Citigroup's provision for income taxes fell by $395 million following changes in the U.S. tax code, which reduced the bank's tax rate to 24 percent in the quarter from 31 percent a year earlier.
The bank's return on tangible common equity was 11.3 percent in the quarter, inching closer to Chief Executive Officer Mike Corbat's goal of 13.5 percent in 2020.
Up to Thursday's close, Citi shares have lost 8 percent of their value for the year, compared with a 5-percent drop in the broader KBW Bank Index <.BKX>.
(Reporting by Siddharth Cavale in Bengaluru and David Henry in New York; Editing by Sriraj Kalluvila and Nick Zieminski)
By Siddharth Cavale and David Henry