Regan got right to the point: "Is Bitcoin a bubble?" Regan asked.

"I guess so," Greenspan said, adding, "You really have to stretch your imagination to infer what the intrinsic value of Bitcoin is. I haven't been able to do it. But if you ask me, 'Is this a bubble in Bitcoin?' 'Yeah, it's a bubble." 

 

People are baffled by this remark.

That's because Greenspan refused to call the housing bubble a bubble, and presided over the dot-com bubble despite seemingly having recognized it as such as far back as 1996, when he made his "irrational exuberance" speech.