What is the Bitcoin halving?
The Bitcoin halving is the programmed 50% reduction of Bitcoin’s block reward that occurs every 210,000 blocks (approximately every 4 years). The mechanism, written into Bitcoin’s code by Satoshi Nakamoto in 2009, controls Bitcoin’s supply issuance rate, ensuring that total Bitcoin supply asymptotically approaches but never exceeds 21 million.
The halving schedule
Five halvings have occurred. (1) November 2012 — block reward 50 → 25 BTC. (2) July 2016 — 25 → 12.5 BTC. (3) May 2020 — 12.5 → 6.25 BTC. (4) April 2024 — 6.25 → 3.125 BTC. (5) Projected 2028 — 3.125 → 1.5625 BTC. The final fraction of Bitcoin will be mined around 2140; after that, miners earn solely from transaction fees.
Halving price cycles
Empirically, Bitcoin’s price has trended upward in the 12-18 months following each halving — the “halving cycle” thesis. The mechanism: reduced supply issuance with stable or growing demand creates supply-demand imbalance. However, the relationship is empirical rather than causal — confounding factors (macro conditions, institutional adoption, regulatory shifts) influence each cycle differently. The 2024 halving coincided with US spot Bitcoin ETF approvals, making isolating the halving effect difficult.
Miner economics
Each halving cuts miner revenue 50% (assuming stable price). Miners with higher hash-rate efficiency and lower energy costs survive; weaker miners exit. Post-halving, mining difficulty adjustments rebalance to maintain ~10-minute block times. Each cycle, miner concentration tends to increase as marginal operators exit.
The 21 million cap
Bitcoin’s total supply mathematically approaches 21,000,000 — but never exactly reaches it due to floor-rounding in reward calculations. Estimates suggest ~20.999998 BTC will ever exist. The cap is the foundation of Bitcoin’s “digital gold” narrative and contrasts with Ethereum’s post-EIP-1559 deflationary dynamics.
Türkiye context
For Türk Bitcoin investors, halving cycles provide a framework for long-term DCA (dollar-cost averaging) strategies and tax-planning around expected appreciation windows. Türk CASP-licensed exchanges should anticipate halving-cycle trading volume increases when planning operational capacity. KVK Article 75 capital gains treatment of crypto remains evolving — sophisticated investors typically structure through DTT-eligible vehicles.
Related: Bitcoin Ordinals, BRC-20 Token, EIP-1559.