What is the circulating supply of op?

Could you please elaborate on the concept of "circulating supply" in the context of cryptocurrency, specifically for the token known as "OP"? How is this metric calculated, and what significance does it hold for investors and traders in the market? Understanding the circulating supply can help assess the token's scarcity, market capitalization, and potential for price appreciation. Could you provide a concise yet informative explanation of this crucial aspect of OP's market dynamics?