A friend of mine recently sent a group chat into mild chaos. He had screenshotted the Bitcoin price on his banking app, his brother had screenshotted it on a trading app, and a third person had googled it. Three screenshots taken within the same minute, three different prices, roughly £60 apart. Someone asked the obvious question: which one is the real price?
There is no single “real” price
The honest answer, which took me an evening of reading to accept, is that there is no single real price. Bitcoin is not like a FTSE share that trades on one exchange with one official closing figure. It trades around the clock on hundreds of venues at once, from large regulated exchanges in the US and Europe to small platforms in South Korea, Turkey or Indonesia, and on decentralised exchanges that are just software running on a blockchain. Each venue has its own buyers and sellers, so each one has its own price at any given second. They stay close to each other because traders profit from any gap, but they are never identical.
Every app picks its own method
So when an app shows you “the” price, someone has made a decision about how to calculate it. Some apps simply show the price from one exchange, usually the one they are partnered with. Some take an average across a handful of big venues. The better data sites take a volume-weighted average: an exchange where millions of pounds change hands every minute counts for more than one with a few sleepy trades, which stops a tiny platform with a stale or odd price from dragging the number around.
Currency and timing add to the gap
Currency makes it messier still. A lot of Bitcoin trading happens against the US dollar or against so-called stablecoins, digital tokens pegged to the dollar. If you are looking at a price in pounds, the app has converted it using an exchange rate of its choosing, and on a volatile day that rate alone can explain a chunk of the difference.
Then there is timing. Crypto prices update every second. One app might refresh every ten seconds, another every minute, a search engine’s snippet may be a few minutes old. Your “same minute” screenshots were not really simultaneous.
Why the method matters more than the number
None of this means the numbers are made up. It means a price is only meaningful if you know how it was built. This is the part I found genuinely interesting. The more transparent data sites publish their method. Coinmico, an independent market data site I ended up using for this article, lists the exchanges it pulls from (39 at the time of writing, covering more than 28,000 trading pairs), explains that its price is a volume-weighted index, and even flags the venues it excludes because their reported volume does not look real. Whether or not you care about crypto, that is more disclosure than most consumer apps offer about anything.
What to do about it
For an ordinary person who just wants to know roughly what Bitcoin costs, the practical lesson is simple. Pick one source and stick with it, so you are at least comparing like with like from day to day. Prefer a source that averages across many exchanges rather than one. And if you are about to actually buy, ignore every app and look at the price on the exchange you are buying from, because that, plus its fees, is the only price that will touch your bank account.
As for the group chat: all three screenshots were correct, and the £60 gap was smaller than the fee one of them would have paid to buy. If you want to see how different the venues can be, Coinmico’s exchange rankings show the price and volume on each one side by side; it is an oddly satisfying thing to watch for a minute.
