How much USDT exists?

Excuse me, could you please tell me how much USDT is currently in existence? I'm quite curious about the total supply of this stablecoin and its impact on the cryptocurrency market. As a layman in this field, I find it intriguing to understand the economics behind it. Could you also explain how its supply is managed and whether there's a limit to its issuance? Thank you for your time and assistance.