Citigroup is setting its sights on the trillions of dollars in assets held by its clients at rival firms. A new effort the bank will announce on Thursday is aimed at gathering those assets-and reflects CEO Jane Fraser's ambitions to lift returns and gain an edge as a wealth manager.

In a push to incentivize existing clients to park more of their cash and investments with Citi, the bank will roll out a feature that provides them with higher savings rates if they keep more of their holdings there.

Fraser and her leadership team have outlined what they view as a $5 trillion opportunity before them: angling for assets they refer to as "off us," or held elsewhere by Citi clients.

The new feature, called Premium Boost, joins a slate of similar initiatives by competitors. This year, Bank of America, U.S. Bancorp, and PNC Financial Services Group have introduced programs aimed at getting customers to consolidate their financial lives with them-not with the bank or brokerage across the street.

Kate Luft, the executive overseeing the rollout, aimed to design the feature with an industry truism in mind: the bar to convince customers to switch banks is high. Citi and other big banks are drawing on the same playbook to expand existing client relationships-and further tether them to one bank-as they confront intensifying competition from digital banks, brokerage firms, and asset managers.

"We are trying to make this as easy as possible," said Luft, the head of U.S. retail banking and the wealth segment known as Citigold, in an interview at a branch at Citi's lower Manhattan headquarters.

Clients access Premium Boost's higher savings rates if they belong to one of the retail bank's relationship tiers of wealth. Every month, those who have between $30,000 and $999,999 at Citi must make $5,000 in direct deposits, or maintain a $25,000 minimum average balance in Citi investment accounts. For those in Citigold Private Client, which requires at least $1 million at the retail bank, they must own a Citi checking account.

Luft hopes the setup is more straightforward than competitors' programs. The banking industry has "lost its way" in putting the onus on clients to see if they qualify for better rates and rewards, Luft said, with tangles of short-term promotions, exclusions, and qualifications. Premium Boost rolls out next month.

The launch underscores U.S. banks' broader strategy as they aim to fend off both incumbent and upstart rivals-especially as a period of higher interest rates has customers shopping around for high-yielding options. Nonbank rivals are also encroaching. A page set up online this year by fund-management giant Fidelity, which offers banking services, captures that dynamic, asking "Do you really need a bank?"

The new feature also shows how Citi is taking on an increasingly offensive, rather than defensive, posture as it nears the end of a yearslong, firmwide turnaround effort led by Fraser. Shares of Citi, the third-largest U.S. bank, have risen to multiyear highs, and the bank bought a small start-up called Kard last month.

Still, the bank remains under a consent order that regulators issued six years ago after finding long-running deficiencies in the bank's internal controls, compliance, and risk management programs.

As part of Fraser's turnaround, known internally as the transformation, she hired Andy Sieg, the former head of Bank of America's Merrill Lynch, to run the global wealth business. Luft reports to Sieg.

"When you think about it, yesterday's struggles to deepen wallet share equal today's massive opportunity to grow. This isn't a build or expansion story, and it is not an expensive bet on new client acquisition," Sieg told investors this past May. "We have the clients. Our challenge is to deepen the relationship by showing them what's possible when they entrust more of their financial life to Citi."

The company declined to specify near-term goals for gathering assets through Premium Boost. Luft said the cost of the program wouldn't impact the expense guidance that Citi provided during its investor day presentation this past May.