Crypto is on fire again. After a deep slump earlier in the year, prices are jumping and new investors are piling in. In a stunning sign of the times, the initial public offering of Circle Internet Group surged some 170% on its first day of trading Thursday.

What exactly does Circle do, and why did it decide to move its headquarters from downtown Boston to lower Manhattan late last year? Here are six things to understand about the company, which manages a "stablecoin" called USDC.

Circle, the company behind the $61 billion stablecoin USDC, made a roaring debut on the New York Stock Exchange Thursday, becoming the first stablecoin issuer to go public and making CEO and cofounder Jeremy Allaire a billionaire.