JPMorgan Chase & Co. recorded a $4.3 billion increase to its allowance for credit losses on Jan. 1 under new accounting rules, near the low end of the range of $4 billion to $6 billion it had previously estimated.

During a call on fourth-quarter earnings, CFO Jennifer Piepszak said the bank "ended up at the low end" as it arrived at more certainty about the macroeconomic forecasts it would use, including a relatively positive baseline scenario.

"We weight multiple scenarios, with the one most likely getting the greatest weight, and that's where you end up with what looks like a reasonably benign outlook," she said.

The increase in the allowance was driven almost entirely by JPMorgan Chase's credit card portfolio, partly offset by a decrease for its wholesale loan portfolio. Under the new current expected credit loss standard, banks must set aside reserves for estimated lifetime losses, and longer-lived consumer loans have explained the bulk of estimates for allowance increases.

Analysts and investors have been anticipating disclosures in fourth-quarter 2019 earnings reports for insight into how CECL will work in practice and how it might affect product design.

Piepszak said that credit loss provisioning at JPMorgan Chase could be incrementally more volatile as macroeconomic forecasts evolve but that the bank does not expect the impact to be material. She also said the company is not planning to change loan pricing because of the new accounting, although that could change.

"We don't foresee, in the near term, any pricing changes. The cash flows with the customer have not changed," she said. Still, reserving upfront imposes a capital cost, and "over time, you could see" an impact on pricing.