Halving
The halving is a programmed event that cuts the Bitcoin block reward in half every 210,000 blocks, approximately every four years. This mechanism enforces Bitcoin's disinflationary monetary policy, gradually reducing new supply until the final satoshi is mined around 2140.
How It Works
When Satoshi launched Bitcoin in 2009, the block reward was 50 BTC. After the first 210,000 blocks were mined (in November 2012), the reward dropped to 25 BTC. In 2016 it halved to 12.5 BTC, in 2020 to 6.25 BTC, and in 2024 to 3.125 BTC. This schedule continues until approximately the year 2140, when the reward will be less than one satoshi and effectively reach zero.
The halving is hardcoded into Bitcoin's consensus rules. No one can change it without a hard fork that the entire network would need to accept. This is what gives Bitcoin its credibility as sound money — the supply schedule is known in advance, immutable, and verifiable by anyone running a full node. There will never be more than 21 million bitcoin, and the halving is the mechanism that enforces this.
Halvings have historically preceded significant price appreciation as the market absorbs the reduction in new supply. But more importantly, they represent a countdown clock. With each halving, Bitcoin becomes scarcer and the stock-to-flow ratio increases. By 2140, all 21 million bitcoin will have been issued, and miners will be sustained entirely by transaction fees.
Key Points
- Block reward is cut in half every 210,000 blocks (~4 years)
- The reward started at 50 BTC and has halved four times as of 2024
- Enforces the hard cap of 21 million bitcoin total supply
- Hardcoded into consensus rules — cannot be changed without network-wide agreement
- Gradually shifts miner incentives from block rewards to transaction fees