The clock keeps counting, and the box has not moved.

Quantum runway counter ticks past ten billion

Updated 18 October 2026

That is a milestone. It is not a protocol change. A counter that tracks the dollar value of legacy P2PKH boxes whose public keys are already exposed has now cleared ten billion US dollars, and the number is rising rather than falling. Treat the figure as a way to time the conversation, not as a switch that flips a box open. Never paste a seed into a watch-only field.

What the counter actually measures

The quantum runway counter is a single number, and like most single numbers in this corner of Bitcoin, it is a lie in a useful direction. The lie is that value is uniform, that a dollar in a 2010 P2PKH box is interchangeable with a dollar in a 2024 P2WPKH box. It is not. The useful direction is that the counter is computable from public data, and that it gives a shared reference point for a debate which otherwise runs on vibes and press releases.

Concretely, the counter takes the set of unspent transaction outputs whose script type reveals the public key on chain at rest, multiplies each by a recent price, and sums. The dominant input has always been early P2PKH outputs from 2009 through 2012, where the pay-to-pubkey-hash construction committed the hash but the spending transaction, or in some pathological cases the coinbase itself, exposed the underlying secp256k1 public key. Once that key is on a public ledger, a sufficiently large fault-tolerant quantum computer running a refined Shor's algorithm can, in principle, recover the private scalar.

The counter does not measure difficulty. It does not measure qubit count, surface code overhead, or logical clock speed. It measures dollars in boxes that cryptography can no longer promise are closed, at a price the market has agreed on this week. Both halves of that statement matter, and both are the kind of thing a previous runway reading has handled before.

By mid-October 2026, with spot trading in the corridor where it has been, the sum cleared ten billion. The first nine billion took the better part of two years to accumulate. The tenth crossed in roughly six weeks. That is the second-order fact worth holding: the counter accelerates because the price accelerates, and the price does not need a quantum computer to climb.

Why ten billion is a round number with teeth

Round numbers are cultural, not cryptographic. AES-128 does not become weaker on a Tuesday, and secp256k1 does not become weaker because a counter prints ten figures. The teeth of ten billion come from the conversation it forces, not the math it enables.

BIP 360, the post-quantum migration draft that has been circulating in various forms since 2024, has always framed its freeze date in terms of runway rather than qubits. The argument runs: if you can name a date by which any plausible fault-tolerant machine could derive a secp256k1 secret from a public key, you can back out a freeze date that gives owners time to move. The runway counter is meant to make that date legible, by attaching a dollar figure to the cost of moving slowly. At ten billion, the cost of moving slowly is no longer a footnote.

There is a second reason the figure has force. The political economy of a Bitcoin fork is dominated by people who hold coins, and the population of people whose coins sit in legacy boxes is, by construction, the population most likely to have stopped paying attention. A counter that prints nine billion is a story for the readers of this site. A counter that prints ten billion is a story for a finance editor, because ten billion is a number that survives a subhead. That is not a flattering reason for a threshold to matter, but it is the real one.

For the avoidance of doubt, the counter is not measuring the value at risk to a quantum attacker. It is measuring the value sitting in boxes the cryptography can no longer vouch for. The difference is between the cost of breaking in and the value of what is behind the door. Door value is the easier number to publish, and it is the one the counter tracks.

Who actually acts on the counter

Three groups watch a figure like this, and they act on it in different ways and on different timescales.

The first group is the small set of people who still hold the keys to early boxes and who have not yet moved them. By construction this is a shrinking set, and the shrinking happens for two reasons. Some have lost the keys, in which case the runway counter is academic. Some have moved the coins already, in which case the counter overstates their exposure. The remainder is a population whose size can be estimated but not enumerated, and whose behaviour is the only thing that can move the counter down rather than up.

The second group is the developer community around the post-quantum migration proposals. For them the counter is a coordination tool, and ten billion is a number they can put in a slide deck without losing the room. BIP 360's freeze date, whenever it lands, will be defended with reference to figures like this, and the figures have to be defensible from a spreadsheet, not a vibesheet.

The third group is institutional. Custodians, ETFs, and balance sheet holders do not sit on legacy P2PKH boxes in any material quantity. Their interest in the counter is reputational and regulatory, and runs in the opposite direction. A counter that climbs is a counter that, one day, will be the headline of a panic they would prefer to have been warned about. Their preferred warning is a published schedule, and the counter is what pressures the schedule to be published.

None of these groups moves the counter directly. The counter moves when the price moves and when coins move, and the coins move when their owners act. The useful thing to say about ten billion is therefore the same thing that was useful to say at nine and will be useful to say at eleven: it is a measurement, not a deadline.

What the counter is not telling you

The counter is silent on the things that actually decide outcomes. It does not know how many of the legacy boxes have lost their keys, because the chain does not record that. It does not know how many of the remaining boxes are watched, in the sense a watch-only wallet is a window rather than an opening, because watching is off chain. It does not know how many of the owners are timing their move to a tax year, a fork, or a price target, because timing is private.

It also does not know how much of the value is held by entities who would, in the event of a credible quantum threat, prefer to destroy their coins rather than see them moved by an attacker. That preference is real, has been signalled in public by figures associated with early mining, and is the kind of thing a counter cannot capture. If the proportion of burners is large, the runway counter overstates the value an attacker can capture. If the proportion of burners is small, the counter is roughly right and the panic is roughly warranted.

Finally, the counter says nothing about the time between a credible quantum demonstration and an actual attack. Published estimates for a fault-tolerant Shor run on a 256-bit elliptic curve have, over the last two years, drifted from comfortably far to uncomfortably near. A single demonstration, even a partial one, would invalidate the assumption that runway and counter can be treated as a slow-moving system. Treat the counter as a weather vane, not a barometer.

What to do with a round number

If you hold the keys to a legacy P2PKH box, the round number is a reminder, not a trigger. The action has been the same since the air gap stopped helping and the same since the QSB draft was published: move the coins to an output type that does not expose the public key at rest, do it before the network freezes legacy scripts, and verify the move on hardware you control rather than a webpage that promises to do it for you.

If you do not hold the keys, the round number is a reminder of a different kind. The thing the counter measures is, in aggregate, the largest single pool of value in Bitcoin that is governed by a known and dated cryptographic assumption, and the assumption is the only thing keeping the box closed. The counter is the way the assumption becomes legible to people who do not read BIPs.

And if you are the kind of person who reads this site, the round number is the cue to refresh the page that shows the counter, notice the direction it is moving, and notice how fast. That is the entire job of the counter, and it is the only job it has ever had. Never paste a seed into a watch-only field.