What Is the Bitcoin Halving?

Roughly every four years, the reward that Bitcoin miners receive for adding a block is cut in half. That event is called the halving, and it is written into Bitcoin's rules. It is the mechanism that makes new supply shrink over time until it stops entirely. You can watch the live countdown on our Bitcoin halving page.

What actually changes

Nothing about your coins changes. What changes is the rate at which new coins enter circulation. The reward started at 50 BTC per block, then fell to 25, 12.5, 6.25 and most recently 3.125. Each halving happens after another 210,000 blocks are mined, which takes about four years at ten minutes per block.

Why it matters

• Supply. The flow of new bitcoin to the market is cut in half overnight. If demand stays the same, less new supply means upward pressure on price.
• Miners. Their revenue halves instantly while their electricity bill does not. Less efficient miners shut down, and the network adjusts difficulty to compensate.
• Attention. Halvings attract media coverage, which historically has brought new buyers.

What history shows

Each of the first three halvings was followed by a major price increase within roughly twelve to eighteen months, and each was also followed by a deep drawdown afterwards. Three data points is not a statistical pattern, and the market now includes ETFs and institutions that did not exist previously. Treat the halving as one input among many, not a guarantee. You can examine what actually happened using our Bitcoin price history tool.

What happens at the end

Halvings continue until the block reward becomes effectively zero, expected around 2140, when the full 21 million supply will have been issued. From then on miners are paid entirely from transaction fees.