PayPal’s chief financial officer, John Rainey, predicted that cryptocurrency will become a popular payment method in the future.

During a sweeping interview with The Wall Street Journal over the weekend, Rainey said that the current volatility with bitcoin and other cryptocurrencies makes it impossible to be a reliable currency for purchase. After all, merchants can have a 10 percent profit margin one day from accepting bitcoin and then see the value decline 15 percent the next day.

Still, Rainey said that in the future there is a “very high likelihood” it will become a popular payment method. “The technology, there is real merit to it. I do think, though, it will be years down the road before we see the kind of ubiquity and acceptance that makes it a form of currency that is used every day,” said Rainey, noting that PayPal was an early adopter of bitcoin as a payment method.

Rainey’s comments come a little more than a month after the digital payments company was showing support for cryptocurrency. In January, during a Facebook Live event between PayPal CEO Dan Schulman and Xapo CEO Wences Casares, Schulman said that “people are paying attention” to cryptos and bitcoin “because it is an interesting experiment.” Should it work out, he continued, “it could change the world,” but added that it could also fail.

During the interview, Casares handicapped the chances of the latter at about 20 percent (if holders put up money they cannot afford to lose), and also said there is a “higher than 50 percent chance that this experiment succeeds.” Should that be the case, time is a key ingredient, noted Casares, and will take several years – give it five to 10. He reiterated his stance that success could mean significant economic consequences – even that a bitcoin could be worth a million dollars.