Greetings, my friend. As of now, there are approximately 18.5 million bitcoins in circulation out of a total supply cap of 21 million. This means that there are still approximately 2.5 million bitcoins left to be mined, which will be gradually released into circulation through a process known as mining rewards.

Mining rewards are a crucial aspect of the Bitcoin ecosystem, as they incentivize miners to maintain the network and secure the blockchain through computational power. As time goes on, the number of bitcoins released through mining rewards decreases, making it harder and harder to mine new coins and contributing to the scarcity of Bitcoin. Thank you for your insightful question.