Every ~4 years, the Bitcoin network automatically cuts the block reward miners receive in half. This programmed supply reduction — the halving — is Bitcoin's most discussed price catalyst, having preceded three massive bull runs. The fourth halving occurred in April 2024.
Bitcoin's code specifies that the block reward halves every 210,000 blocks. At Bitcoin's ~10-minute block time, this works out to roughly every 4 years. The reward started at 50 BTC per block in 2009 and has halved three times:
This continues until all 21 million Bitcoin are mined — projected around the year 2140. By then, miners will earn only transaction fees.
| Halving | Date | Pre-halving Price | Peak Price (18mo after) | Gain |
|---|---|---|---|---|
| 1st | Nov 2012 | ~$12 | ~$1,100 | +9,000% |
| 2nd | Jul 2016 | ~$650 | ~$20,000 | +3,000% |
| 3rd | May 2020 | ~$9,000 | ~$69,000 | +667% |
| 4th | Apr 2024 | ~$65,000 | TBD | Ongoing |
Basic economics: with demand constant or growing, cutting the rate of new supply reduces selling pressure from miners. Before the halving, miners receive X BTC/day that they may sell to cover electricity and hardware costs. After the halving, they receive X/2 BTC/day — meaning less forced selling into the market.
Additionally, the halving generates enormous media attention, triggering retail FOMO and institutional allocation reviews. The narrative effect is arguably as powerful as the supply mechanic itself.
The halving cuts miner revenue in half overnight. Inefficient miners with high electricity costs are immediately unprofitable and must shut off. This temporarily reduces the network hashrate (the "miner capitulation" phase), but Bitcoin's difficulty adjustment algorithm automatically lowers the mining difficulty within two weeks, restoring profitability for the remaining miners.
The 2024 halving pushed miners toward higher-efficiency ASICs and geographic regions with cheaper energy. Those that survived are now more profitable than ever as BTC price has risen significantly from the $65,000 pre-halving level.
Polymarket ran multiple markets around the April 2024 halving — including "Will BTC hit $100K in 2024?" and "Will BTC be higher or lower 6 months post-halving?" These markets offered valuable crowd-sourced probability estimates that supplemented traditional technical analysis. Tracking these markets is one way prediction market traders express cyclical views.
Each successive halving produces a smaller percentage supply shock relative to the total outstanding supply. Additionally, with Bitcoin ETFs now absorbing millions of BTC in institutional demand, the marginal impact of reduced miner selling may be lower. Some analysts argue the 2024 cycle will produce a smaller peak-to-trough gain than previous cycles — others argue that institutional demand creates a new demand floor that more than compensates.