Glossary
What is the Bitcoin halving?
In one sentence
A halving is the scheduled event where Bitcoin's mining reward is cut in half, slowing the rate at which new coins are created.
Bitcoin’s supply is released through mining rewards, and roughly every four years — precisely, every 210,000 blocks — that reward halves. It started at 50 bitcoin per block, and has stepped down repeatedly since. This continues until the 21 million cap is reached, expected around 2140.
The mechanism enforces the supply schedule without anyone administering it. It is written into the protocol and applies automatically.
Halvings attract a great deal of price speculation, on the reasoning that reduced new supply against steady demand should push prices up. Past halvings have been followed by large rallies, but the sample is tiny — four events — and each occurred in different macroeconomic conditions. The event is also entirely predictable, which means markets have had years to price it in.
Treat confident claims about what a halving will do to the price with caution. The supply effect is real and mechanical; the price effect is speculation.
For example
The halving is fully known in advance, which is exactly why it is difficult to argue it is unpriced.