JPMorgan Chase's Reserve credit card should deliver a good return despite it initially costing the bank at least $200 million to $300 million, CEO Jamie Dimon told CNBC on Wednesday.

Dimon was referring to the bank's Chase Sapphire Reserve, introduced last summer, that offered a sign-up bonus worth $1,500 to people who spent $4,000 on the card in the first three months.

The bonus was widely popular and brought the card a lot of attention, but it also caused the bank to take a hit to its fourth-quarter earnings after handing out so many perks.

Dimon, speaking to CNBC at the World Economic Forum in Davos, Switzerland, said the card was in fact successful and that he wishes the bank lost more money.