Bitcoin’s fourth halving cut the block subsidy to 3.125 BTC

The fourth subsidy era ended

At 8:09:27 p.m. Eastern Daylight Time on April 19, 2024, Bitcoin block 840,000 joined the chain and activated the network’s fourth scheduled subsidy reduction. The block header carries a timestamp of 00:09:27 UTC on April 20, a calendar-boundary difference worth making explicit. Coinburn’s archive uses America/New_York dating, so this record is assigned to April 19.

The change cut the new bitcoin available in each valid block from 6.25 BTC to 3.125 BTC. It did not depend on a company announcement, regulator or discretionary vote. Bitcoin Core version 27.0 expresses the subsidy rule by dividing block height by the 210,000-block halving interval and shifting the initial 50 BTC subsidy downward once for each completed interval. At height 840,000, the calculation entered its fourth reduction.

That distinction also separates the block subsidy from a miner’s total block revenue. Miners could still collect transaction fees in addition to the 3.125 BTC subsidy. Saying miner revenue was automatically cut in half would therefore be inaccurate: the subsidy was halved, while fee income, bitcoin’s dollar price and the number of blocks found could all vary.

A mechanical supply change with business consequences

The immediate monetary effect was clear. Using the protocol’s approximate target of one block every 10 minutes, 144 blocks would be expected in 24 hours. Multiplying by the subsidy gives a theoretical issuance pace of 900 BTC per 144-block interval before the change and 450 BTC afterward. That is a calculation, not an observation of any particular UTC or New York trading day; actual block production varies because proof-of-work arrivals are irregular.

For mining companies, the event reset the operating equation. A miner with unchanged computing power and the same share of network production would earn half as much newly issued bitcoin per block won, before fees. Whether an operator remained profitable still depended on machine efficiency, electricity and financing costs, network difficulty, transaction fees and bitcoin’s exchange rate. The halving therefore created pressure, not a guaranteed shutdown or consolidation outcome.

For investors, the event reduced one source of prospective sellable supply, but it did not create a mechanical price rule. The three earlier halvings in 2012, 2016 and 2020 offered only a small historical sample, and comparisons across them mixed very different liquidity, leverage, regulation and macroeconomic settings.

The market watched from a new institutional setting

The April 19 halving arrived after the U.S. Securities and Exchange Commission’s January 10, 2024 order allowed national securities exchanges to list and trade shares of several spot bitcoin exchange-traded products. That did not alter Bitcoin’s issuance code, but it gave U.S. investors a newly approved exchange-traded channel through which demand could meet the post-halving supply schedule.

Contemporaneous price snapshots showed no immediate breakout. Reuters, relaying CoinGecko data after the event, reported bitcoin down 0.47% at $63,747. The Associated Press separately cited a Friday-night CoinMarketCap level of about $63,907. Those figures are snapshots from different aggregators, not a single official closing price: bitcoin trades continuously, venue coverage differs, and neither observation proves the halving caused the move.

What April 19 established

The verified conclusion is narrow but consequential: block 840,000 executed the monetary rule and reduced the subsidy to 3.125 BTC. April 19 evidence did not establish the halving’s eventual effect on price, hash rate, miner failures or market concentration. Those were forward questions requiring later data, not facts available from the event itself.