Bitcoin's First Halving: The Day It Cut Its Own Paycheck in Half on Purpose

At 15:24:38 UTC on 28 November 2012, a Czech mining pool called Slush's pool added block 210,000 to Bitcoin's public ledger. It was paid 25 brand-new bitcoin for the job. The block before it, mined by a rival pool called BTC Guild about 23 minutes earlier, had paid 50. Nobody announced the change, nobody voted on it and nobody could have stopped it. The rule had been in Bitcoin's code since Satoshi Nakamoto switched the network on in January 2009.

That was the first halving. One bitcoin cost about $12 that day, according to price histories kept by StatMuse and TradingView. Miners around the world had been sharing roughly 3,600 new coins a day, worth about $43,000. From that block on they shared about 1,800, worth about $21,600. Around 10.5 million bitcoin existed, exactly half of the 21 million that will ever be made, so the flow of new coins fell from about 12.5% of the supply a year to about 6%. A year later the price had passed $1,000, and the halving had a reputation it has never lost.

A pay cut written into the rules

Bitcoin has no company and no central bank. Its ledger is kept by "miners": people and firms running computers that compete to add the next page of transactions, called a block, roughly every ten minutes. The winner of each round is paid in two ways: a fixed allowance of new bitcoin, called the block reward, plus the fees users attach to their payments. Most miners join a pool, a syndicate that combines computing power and splits the winnings, much like an office lottery syndicate.

The halving is a clause in the founding rules. Every 210,000 blocks, about every four years, the block reward is cut in half. Think of a company whose charter forces it to issue half as many new shares every four years, whatever the share price does and whatever the board thinks. The cuts continue until the reward shrinks below one satoshi, the smallest unit of bitcoin (a hundred-millionth of a coin, the equivalent of a cent), which is expected around the year 2140. Supporters call this a fixed monetary policy. Critics call it a pay cut for the people who keep the network running.

Graphics cards in bedrooms

In 2012 mining was still a hobby that paid. Most of the work was done on graphics cards, the chips gamers buy to run video games, sitting in bedrooms, garages and student flats. The Bitcoin Wiki records that the winning answer for block 210,000 came from a member of Slush's pool going by the name "laughingbear", using a Radeon HD 5800 series card after less than a week of mining. The pool itself had been started in 2010 by the Czech programmer Marek Palatinus, known as Slush, as the first of its kind. It still runs today under the name Braiins Pool.

The first halved block did not pay its miner less than the old ones. Its 457 transactions carried 13.56 bitcoin in fees, including a single payment that handed over 7 bitcoin, so the block paid 38.56 bitcoin in total, according to the Blockstream and Blockchain.com block explorers. Every block after it went back to the normal pattern of 25 coins plus small change.

Before the date, some miners predicted that half the machines would switch off, since half the income was gone overnight. The network has a thermostat for that: every 2,016 blocks, about two weeks, it resets the difficulty of the puzzle so blocks keep coming every ten minutes however many machines are running. Block data show the difficulty stood at 3.44 million when the halving arrived, fell 2% on 10 December and 11.6% on 26 December as some miners gave up, then rose 9% on 8 January 2013. The network shrank for a month and carried on.

What ended the bedroom era was not the halving but a new kind of machine. In early 2013 a Chinese team led by Zhang Nangeng began shipping Avalon miners built on ASICs, chips designed for one job only, which did the work of dozens of graphics cards for the same electricity. It was the difference between a pocket calculator and a factory. Avalon's maker later became Canaan, which listed its shares on Nasdaq in 2019.

A small, scrappy market

Bitcoin in late 2012 was a small business with big troubles. In August the Bitcoin Savings and Trust scheme run by Trendon Shavers, later charged by the US Securities and Exchange Commission as a Ponzi scheme, stopped paying out. In September the exchange Bitfloor was hacked for about 24,000 bitcoin. On 27 September a group including the developer Gavin Andresen, Mark Karpeles of the Mt. Gox exchange, the investor Roger Ver and the entrepreneur Charlie Shrem launched the Bitcoin Foundation to clean up the currency's reputation.

There was good news too. On 15 November, two weeks before the halving, WordPress.com, the blogging service run by Automattic, began accepting bitcoin through the payment firm BitPay, saying PayPal blocked users in more than 60 countries. Most trading ran through Mt. Gox in Tokyo, the biggest bitcoin exchange (an exchange works like an online broker), run by Karpeles.

What came after

The price did what halving believers now expect. During the Cyprus banking crisis in spring 2013, when ordinary savers had deposits frozen, bitcoin jumped to $266 in April before crashing back. In the last week of November 2013, almost exactly a year after the halving, it passed $1,000 on Mt. Gox. A month later China's central bank cut its banks off from bitcoin and the price halved. In February 2014 Mt. Gox itself collapsed, with about 850,000 bitcoin missing.

The same shape followed later halvings. Bitcoin was about $650 at the July 2016 halving and reached about $20,000 in December 2017. It was about $8,600 at the May 2020 halving and reached $69,000 in November 2021. It was about $64,000 at the April 2024 halving and reached about $126,000 in October 2025. In mid-October 2026, 18 months after that last cut, it traded around $82,000, according to CoinGecko.

Sceptics have good arguments. Four halvings are four data points, not a law. The 2013 rally also had Cyprus, Silk Road and, according to a study published in the Journal of Monetary Economics in 2018, suspicious trading by automated accounts on Mt. Gox that pushed the price up. And the gains shrink each time: roughly 90-fold after 2012, about double after 2024. The halving is the most watched calendar date in crypto. It is not a promise.