Halving
A halving is the scheduled event, roughly every four years, when Bitcoin’s new-coin block reward is cut in half.
In depth
It happens every 210,000 blocks: 50 → 25 → 12.5 → 6.25 → 3.125 BTC and so on until around the year 2140. Halvings enforce Bitcoin’s hard cap of 21 million coins and are closely watched because they shrink new supply overnight. Many other coins copy the idea with their own schedules.
Why it matters
Halvings are among the most significant recurring events in crypto market cycles.