Cycles & Supply
Milestones
The events that shaped Bitcoin, in the order they happened. Each entry carries the date, what occurred, and why it mattered — the last of those being the part that a bare chronology leaves out.
2008-2025Source: Bitcoin protocol history, exchange records and public filingsDates are the event dates, not the dates of first reporting
A chronology is only as useful as the selection behind it. This timeline includes protocol changes that altered what the network could do, market events that changed who held the asset, and adoption events that changed who could buy it. It leaves out price records, which belong on the price history page, and it leaves out the many small events that mattered to participants at the time but did not change the trajectory.
Filter the timeline
Showing 16 of 16 milestones.
Timeline
- ProtocolEarly years
The Bitcoin whitepaper is published
An author writing as Satoshi Nakamoto posts a nine-page paper to the cryptography mailing list describing a peer-to-peer electronic cash system that replaces a trusted third party with a chain of proof-of-work. The paper frames the double-spend problem as a distributed timestamping problem and proposes the longest-chain rule as its resolution.
- ProtocolEarly years
The genesis block is mined
Block zero is created with a coinbase message quoting a newspaper headline about bank bailouts, a timestamp that fixes the network's starting point and a statement of intent. The fifty bitcoin it awards are unspendable by construction, so the genesis subsidy never enters circulation.
- ProtocolEarly years
The first bitcoin transaction
Satoshi sends ten bitcoin to Hal Finney in block 170, the first transfer between two parties other than the miner. The transaction demonstrates that the scripting system can move value without any intermediary, which is the property the whole network exists to provide.
- AdoptionEarly years
Ten thousand bitcoin buy two pizzas
Laszlo Hanyecz pays ten thousand bitcoin for two pizzas delivered to his home, the first documented purchase of a physical good with the currency. The date is now observed as Bitcoin Pizza Day and is the standard illustration of how far the unit's purchasing power has travelled.
- MarketEarly years
Mt. Gox opens as an exchange
A site originally written to trade Magic: The Gathering cards is repurposed into a bitcoin exchange and quickly becomes the largest venue by volume. Its dominance concentrates price discovery in a single operator for the next three years.
- ProtocolEarly years
The first halving cuts the block subsidy
At block 210,000 the subsidy falls from fifty bitcoin to twenty-five, the first scheduled reduction in new supply. The event establishes that the issuance schedule written into the code is executed by the network without any authority deciding to do so.
- MarketEarly years
The first retail mania peaks near $1,150
A year in which the price rose from roughly thirteen dollars to more than a thousand ends with a peak at the end of November. The subsequent collapse of Mt. Gox in early 2014 turned the episode into the template for every later boom and bust.
- MarketEarly years
Mt. Gox suspends withdrawals and files for bankruptcy
The exchange halts withdrawals, then discloses the loss of roughly 850,000 bitcoin, and enters bankruptcy in Japan. The failure removes the largest venue from the market and forces the ecosystem to spread trading across many smaller exchanges.
- ProtocolGrowth
The second halving cuts the subsidy to 12.5 bitcoin
At block 420,000 the subsidy halves for the second time. The reduction arrived with the network's hashrate at a record high and with a maturing derivatives market, and it preceded a sustained advance through 2017.
- ProtocolGrowth
Segregated Witness activates
A soft fork that moves signature data out of the transaction's main body takes effect, raising effective block capacity and enabling the Lightning Network. The change followed years of debate over how to scale the base layer.
- MarketGrowth
The 2017 cycle peaks near $19,900
Retail interest, a wave of new exchanges and the launch of regulated futures at the end of the year carry the price to its then all-time high. The twelve months that followed erased more than eighty per cent of that value.
- MarketGrowth
The COVID crash removes half the price in a day
A global flight from risk assets drives the price down by roughly fifty per cent in a single session, the sharpest one-day fall in the market's history. The recovery was faster than any previous drawdown, and the episode is the standard case study in the asset's liquidity under stress.
- ProtocolInstitutional
The third halving cuts the subsidy to 6.25 bitcoin
At block 630,000 the subsidy halves again, reducing annual issuance to roughly 1.8 per cent of circulating supply. The event coincided with the arrival of corporate treasuries and listed funds as buyers.
- AdoptionInstitutional
El Salvador adopts bitcoin as legal tender
The first country to do so passes a law recognising the asset as legal tender alongside the US dollar and launches a state wallet. The move marks the beginning of sovereign adoption as a distinct category of demand.
- AdoptionInstitutional
US spot bitcoin ETFs are approved
The Securities and Exchange Commission approves the first US-listed spot bitcoin exchange-traded funds, which begin trading the following day. Regulated, brokerage-accessible exposure brings a new class of buyer and a persistent daily flow signal into the market.
- ProtocolInstitutional
The fourth halving cuts the subsidy to 3.125 bitcoin
At block 840,000 the subsidy halves for the fourth time, taking annual issuance below one per cent of circulating supply for the first time. The event is the first to occur with a US spot ETF market already trading.
Reading the timeline against the record
Two patterns are visible once the entries are laid out in order. The first is that protocol events and market events have run on different clocks. The halvings arrived on schedule every four years regardless of what the price was doing, while the market events clustered around them without any fixed relationship. The halving record shows the supply side of that; the cycle analysis takes up the question of whether the two clocks are connected.
The second is that adoption events have become less frequent and more consequential. The early years produced a steady stream of firsts — the first transaction, the first exchange, the first purchase of a physical good — each of which mattered enormously at the time and none of which changed the network's capabilities. The later entries are fewer and larger: a sovereign adopting the asset as legal tender, a regulated spot market opening in the United States. The timeline is thinning out, and the entries that remain are heavier.
The most recent chapter is the 2025 cycle. Bitcoin began the year under pressure and fell to a low of $80,600 on 21 November 2025, then recovered to set its record high of $126,198 on 6 October 2025 before the fourth-quarter correction took hold and the year closed at $87,508.83 on 31 December 2025. The sequence is worth reading against the earlier entries rather than in isolation: the peak arrived roughly eighteen months after the April 2024 halving, in keeping with the lag the completed cycles showed, and the correction that followed was shallower than the declines of 2018 and 2022. Those figures are drawn from the same curated record as the yearly returns and the historical data tables, and they carry the same vintage.
For the price record behind these events, the daily price history and the yearly returns are the two series to read alongside this page. The data sources and methodology page records where each series comes from and how it is prepared.