I have researched Bitcoin for a long time and one thing that always stands out to me is its fixed supply. From the beginning, Satoshi Nakamoto designed Bitcoin so that only 21 million coins will ever exist. It will not have unlimited printing like traditional money. This is the main reason many people compare Bitcoin to gold. It becomes scarce by design.
In my search, I found that as of August 2025, around 19.91 million bitcoins have already been mined. That means almost 95 percent of the total supply is already in circulation. New bitcoins are currently created as rewards for miners, and right now miners receive about 3.125 BTC roughly every 10 minutes. This reward keeps getting smaller because of something called the halving, which happens about every four years. Because of this system, the last bitcoin is expected to be mined around the year 2140.
I start to know about that many people wonder what will happen when no new bitcoins are created. The simple answer is that mining will not stop. It will have a different reward system. Today miners earn from two things, new bitcoins and transaction fees. After 2140, they will earn only from transaction fees paid by users who send Bitcoin.
This means transaction fees will become more important. If many people are using Bitcoin, miners will still have strong income from fees. If usage grows over time, they become financially motivated to keep securing the network. But if fees are too low, some miners might leave, which could reduce security. However, Bitcoin adjusts its mining difficulty automatically. If miners leave, mining becomes easier for the remaining ones, and blocks will still be produced roughly every 10 minutes.
Another important thing I discovered is that not all mined bitcoins are actually usable. Studies suggest that up to 20 percent of Bitcoin may be lost forever because people lost their private keys or forgot their wallets. That means the real available supply is even smaller than the official number. This makes Bitcoin even more scarce over time.
In simple words, when all bitcoins are mined, the system will not collapse. It will have no new coin creation, but it will continue running on transaction fees. The security of the network will depend on how much people use it and how valuable those fees become. Bitcoin was built to think far into the future. Even though 2140 feels very far away, the foundation for that moment is already written in its code today.