The Double Spend Problem, and Why Every Earlier Attempt Needed a Referee
A file can be copied perfectly and for free, which is exactly the property you do not want in money.
ExplainerOrigins
00A diffusion index of fifteen years
Crypto history, above and below the line.
Fifty is the line between expansion and contraction. Fifteen years of crypto is a sequence of things crossing it in both directions, and almost none of the people living through it could tell which side they were on.
A purchasing managers' index is not a price. It is a count of how many respondents said a thing got better rather than worse, and fifty is the point where those two groups are the same size. Above it the thing is expanding. Below it the thing is contracting. The number itself carries no information about size, only about direction.
That is the most useful lens anyone has for crypto, and almost nobody uses it. Capital, attention, credit, belief, users, developers and regulation have each crossed that line more than once since 2008, in both directions, and the crossings rarely happened at the same time as each other or at the same time as the price.
So every piece on this site is written to answer three questions. What was expanding. What was contracting. And who, at the time, could actually tell. The third one is usually the interesting one, because the answer is normally that almost nobody could, including the people whose later accounts say they did.
01The eras, and what defines each one
The spans below are approximate and say so. Era boundaries in crypto are contested, most of the confident ones were drawn after the fact by whoever was writing the retrospective, and this site does not state a contested boundary as a fact. What defines a period here is what was happening in it.
Origins
Expanding
roughly 2008 to 2011
A paper, a mailing list and a client nobody was using yet. Almost everything from this period survives as a document, which is why it is the best documented era and the one most often misquoted.
3 pieces
Early exchange
Both at once
roughly 2011 to 2014
The first places to buy the thing, and the first places to lose it. Custody arrived years before anybody had worked out what custody meant.
1 piece
The token sale era
Expanding
roughly 2016 to 2018
Programmable issuance met an audience with no way to price it. This is where the gap between what a document promised and what a contract did became the whole story.
nothing published yet
On-chain finance
Expanding
roughly 2019 to 2021
Market structure rebuilt as public code: pools instead of books, incentives instead of intermediaries, and a new class of failure that nobody had a name for yet.
1 piece
Institutional arrival
Both at once
roughly 2020 to 2022
Balance sheets, funds and regulated wrappers. The interesting question is not that institutions arrived, it is what they were and were not willing to hold directly.
nothing published yet
After the collapse
Contracting
roughly 2022 onward
A sequence of failures that were reported as market events and turned out, in the filings, to be bookkeeping. The record here is unusually good because so much of it went through a court.
nothing published yet
02Recently published
Half of the Whitepaper's Bibliography Is About Timestamping Documents
The reference list is the least read page of the most read document in the subject, and it points somewhere other than money.
Primary sourceOrigins
The constant product formula is not an equation, and k does not stay constant
The invariant everybody quotes is an equality. The one the code enforces is not, and the difference is where the money comes from.
ExplainerOn-chain finance
Mt. Gox: the coins were already gone before the story was told
The exchange said a bug in Bitcoin took 850,000 coins in February. The chain says at most a few hundred could have gone that way.
PostmortemEarly exchange
The Bitcoin whitepaper does not contain the words everyone quotes from it
Open the file, search it, and most of the vocabulary that the last fifteen years attached to it is simply absent.
Primary sourceOrigins
03What this site does not do
It quotes no price.
Not a market capitalisation, not a valuation, not a figure for what anything was worth on a given afternoon. The history is what happened and what the record says; a chart is a different site.
It makes no forecast.
No target, no view on what is cheap, no prediction. Everything here is written with hindsight the people involved did not have, which is a reason for humility rather than a licence to extend the line.
It invents nothing.
No date, no quote and no claim about what a named person said, unless it is verifiable. Where a claim is contested the contest is named. Where a source is dead the piece says so, and says what it said.