"One of the fictions here is that the marketing cost ... gets booked over 12 months. The benefit of the card gets booked over 7 years. The card was so successful it cost us $200 million, but we expect that to have a good return on it. I wish it was a $400 million loss," the chief executive said on "Squawk on the Street."
Earlier this month, the bank said it planned to cut the card's bonus in half, and that Jan 12. would be the last day people could earn it by applying online.
On Friday, the bank reported fourth-quarter earnings that pushed well past analysts' expectations.
The stock has been near 52-week highs since mid-December. Fridays' report marks the bank's first results since the Federal Reserve raised its key interest rate target in a year. The Fed is expected to raise them again three times this year.
Bank stocks have rallied in recent months on expectations that President-elect Donald Trump will eliminate regulations put in place after the 2008 financial crisis.