The ecosystem around bitcoin is still changing, but U.S. Commodity Futures Trading Commission Chairman J. Christopher Giancarlo said the popular cryptocurrency is part currency, part security and part digital coin.

"Bitcoin and a lot of its other virtual currency counterparts really have elements of all of the different asset classes, whether they're meeting payment, whether it's a long-term asset," Giancarlo told CNBC on "Fast Money" Monday, live from the annual Milken Conference in Los Angeles.

"We see elements of commodity in it that are subject to our regulations, but depending on which regulatory regime you're looking at, it has different aspects of all of that," he said.

Giancarlo went on to say that there are certain aspects of bitcoin that look similar to an asset like gold.

"Only it's virtual," he said. "It's digital."

One key point, he said, is that bitcoin may not be an ideal form of payment. Rather, bitcoin would be better suited for a long-term buy and hold strategy.

The CFTC , as well as the U.S. Securities and Exchange Commission, Giancarlo pointed out, operate under rules and regulations that were established in the 1930s. In contrast, bitcoin, less than 10 years old, is still relatively new.

"At the end of the day, it's for Congress, and not regulators, to decide whether new policies should be evolved for these new asset classes," he said.

Bitcoin hoovered around $9,000 Monday evening.