Halving cycles

The grey line is bitcoin's price on a logarithmic axis, and each dashed vertical marks a halving: the four that have happened, and those still ahead labelled with an estimated year. The axis runs past today to the next halving, so the part of this cycle still to come is drawn as empty space.

The switch above the chart picks the window: this cycle, from the last halving, where it opens; the last two cycles; or all of them, which also reaches past the next halving to the one after. Over the plot a countdown gives the blocks left until the next halving and an estimate of the days at ten minutes a block, and the bar shows how much of the 210,000-block epoch has been mined. The small squares riding the bar are the transactions waiting in the mempool, one for each block's worth up to six, when that feed answers.

Hovering any day shows its close.

Every block pays its miner a subsidy of new bitcoin, and every 210,000 blocks, about four years, the subsidy halves. It began at 50 bitcoin, and fell to 25 on 28 November 2012, to 12.5 on 9 July 2016, to 6.25 on 11 May 2020 and to 3.125 on 20 April 2024. The next halving, at block 1,050,000, cuts it to 1.5625. Its date depends on how fast blocks are found, which is why the countdown gives the blocks exactly and the days as an estimate.

In each finished cycle the price made its top between about a year and eighteen months after the halving, by the table's count, and then fell by three quarters or more. Each top was a smaller multiple of the halving-day price than the last.

Four cycles are a small sample, and they have not repeated exactly: each has had its own length, height and depth. The chart draws the next halving as a date on the axis, not as a promise about the price.

The price is Perly's own daily record, each close dated to the day it was made, and the halving days are the days they happened, in UTC. The block countdown reads the height of the chain's tip, and the days are that count at ten minutes a block.