Halving

A halving is a pre-programmed event, built into some blockchains' code, that cuts the reward miners receive for adding new blocks by 50%. Bitcoin is the best-known example, halving its block reward roughly every four years (every 210,000 blocks) as part of a fixed schedule that will cap its total supply at 21 million coins. Halvings reduce the rate of new coin issuance, which — assuming steady or growing demand — is a key part of the scarcity argument some investors make for these assets. A halving affects future issuance only; it doesn't lock or change coins already in circulation.