Apple's capital return plan will get much larger, according to one Wall Street firm.

Citi Research reiterated its buy rating for Apple shares, saying the company will use tax reform proceeds to significantly increase its stock buyback and dividend program.

"We do expect volatility ahead as consensus estimates calibrate to lower March and June quarters given more tempered demand for iPhone X," analyst Jim Suva wrote in a note to clients Wednesday. "Looking ahead, we expect investor focus to be on the impact from Apple's capital returns strategy, which we estimate could be a $100 billion increase, the 2H18 lineup, and continued strength in Apple's Services segment."

The company's stock rose 0.7 percent Thursday.

Suva reaffirmed his $200 price target for Apple shares, representing 16.5 percent upside to Wednesday's close.

The analyst predicts the company on its next earnings call will raise its capital return program to about $400 billion from its current $300 billion authorization. Suva said a $100 billion increase is double the amount Apple has added in each of the previous two years.

As a result, the analyst said Apple will more than double its annual share buyback, which averaged $32 billion a year in the last five years.

"We believe that the shares remain attractively valued relative to the market and can undergo sustainable multiple expansion," he wrote.

Apple is slated to report its fiscal second-quarter earnings results on May 1, according to its website.