Laszlo Hanyecz writes on the Bitcoin Talk forum that he will pay 10,000 bitcoin for two pizzas.
2
The payment
In block 57,043, a transaction gathers 131 coins and pays 10,000 BTC in a single output.
3
The report
Laszlo posts on the forum that he traded 10,000 bitcoin for pizza, and thanks jercos.
The offer and the report are on the forum, and the payment is on the chain. With this payment, Satsumap’s analysis gets it wrong (sheets 05 and 12).
02
Before we start
Six words to read the chain
Input
The coin a transaction spends. It is spent whole, like a banknote.
Output
A new coin the transaction creates, with its amount and its lock: who can spend it.
Address
A short way of writing a lock, like 1XPTg…. In 2010 many coins had no address, and their lock was the full public key.
Coinbase
The first transaction in each block. It creates new bitcoin for whoever mined it. In 2010, 50 BTC.
Change
What is left over from the banknote, returned to the payer in a separate output. This payment has none.
Consolidate
To gather many of your own coins into one. It has the same shape as a payment with no change.
On the chain, consolidating and paying with no change look the same. This payment is an example.
03
May 22, 2010, 18:16 UTC · Block 57,043
131 coins, a single payment
131inputs, each from a different transaction
1address they all come from
0change outputs. What is left over goes as the fee
2transactions in the block: the coinbase and this one
TXID a1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d. Why 0.99 BTC was paid in fees, the chain does not say.
04
How it looks
The payment in Satsumap
On the left, the coins coming inThey all say 1XPTgDRh…atrvH4: the same address. Eleven are shown; the other 120 wait in “+120 more”.
In the middle, the transactionThe circle is the payment. Above it, the CONS tag, for consolidation.
On the right, the only output10,000 BTC to 17SkEw…. No output goes back to the address that paid.
To explore it: satsumap.citadellhost.com, search for the TXID a1075db5…f5d48d.
05
Satsumap’s mistake
Satsumap gets it wrong
What the app says“Consolidation”, with “high confidence”. And the “?” adds that it is “a fact read straight from the data, not a deduction”.
What is a factThat it has 131 inputs and one output. It is read straight from the chain.
What is a deductionThat someone is gathering their own coins and the 10,000 still belong to whoever paid. The app had a fact against it, because the output goes to an address that is not among the inputs.
What happenedIt was a payment to someone else. The forum and the interview with jercos say so.
Until Oct 20, 2026, the Inspector’s “Spot a consolidation” technique was practiced with this very payment. What happens if you believe the label, on sheet 12.
06
Who is who
Why this transaction?
WHAT THE CHAIN SHOWS
The amountExactly 10,000 BTC, in a single output.
The day and timeMay 22, 2010, 18:16 UTC, one hour before the report on the forum.
No namesOnly the address that pays and the one that gets paid.
WHAT IS KNOWN FROM OUTSIDE
“I just want to report that I successfully traded 10,000 bitcoins for pizza. […] Thanks jercos!”
Laszlo, Bitcoin Talk, May 22, 2010.
Laszlo does not give the TXID. A 2015 interview with jercos gives it, and also says which address each of them used. That part is written by the interviewer, not by jercos. The Bitcoin Wiki gives the same TXID.
The chain is consistent with that attribution and does not prove it. All the sources use this transaction, and none of them proposes another.
07
Going back
Where the 131 coins come from
Group
Coins
Total
Arrived at 1XPTg…
Large, from 80 to 3,753.88 BTC
20
9,999.88 BTC
from Apr 15 to May 22, 2010
Small, 0.01 BTC each
111
1.11 BTC
on Apr 18, 2010, in under two hours
1
None is a coinbase
All 131 reached that address through a transfer. None was created by mining right there. That is why we look one hop further back.
2
One more hop
The large ones lead to coinbases (next sheet). The small ones lead to 111 different addresses, and that is where we stop.
The rule of this case is to go one more hop when a coin was transferred. If there is still no coinbase there, we stop and say so.
08
Going back · the large ones
6,100 BTC from 122 coinbases
Coins created by mining16 of the 20 large ones come from transfers that only gather coinbases: 5,750 BTC. Three others mix coinbases with transfers.
122 different keysEach coinbase pays the key chosen by whoever mines. Whoever made each transfer held the keys to its coinbases.
What does not reach a coinbase3,899.88 BTC come from transfers. We stop there.
INFERENCE
On Aug 4, 2010 Laszlo wrote that he could no longer keep paying for pizzas “since I can’t generate thousands of coins a day anymore”. It is consistent with him having mined those coinbases. The chain shows keys that collected rewards and transfers that gathered them, not a person.
The numbers add up: 6,100 from coinbases + 3,899.88 from transfers + 1.11 from the small coins = 10,000.99 BTC, what goes into the payment.
09
Going back · the small ones
111 coins of 0.01: not known
Apr 182010, the day they all arrived, between 17:57 and 19:46 UTC
111transfers, each from a different address
0.01 BTCto 1XPTg… in each transfer, and the rest to another address
2transfers spend the other output of an earlier transfer
What the chain showsIn two cases, one transfer uses what was left of another. That each pair belongs to one wallet is an inference. For the rest, it does not say whether it was one person or many.
What it does not showWho sent them and why. This case does not speculate about it. A month later, those 111 coins went into the pizza payment.
Added up, the 111 small coins are 1.11 BTC of the 10,000.99 that go into the payment.
10
Going forward
After 9 minutes, it splits in two
9 min 37 safter the payment, the first spend: in the next block
5,777 + 4,223the two parts it splits into
45 dayslater, on Jul 7, 2010, the two parts are spent together again
0in fees at each of these steps
After coming back together, the 11,022 BTC split into 5,500 and 5,522. We stop there, because after the one who got paid, nobody has a name.
11
Jul 7, 2010 · Block 64,683
The two parts, the same wallet
What it showsTo spend a coin you need its key. If two coins go into the same transaction, whoever built it held both, unless several people built it together, as in a CoinJoin.
What it does not showWhose wallet that is. jercos said in 2015 that he spent the 10,000 “fairly quickly”. The chain does not say whether they already belonged to someone else.
In yellow, the coins locked to a bare public key, with no address: the 4,223 and two of the other 18. They all go in with the 5,777 into 9e744590…dd1957.
12
If you believe the label
How a chain analysis fails
Step
The rule
What it concludes
Is it true?
1
Common input
The 131 inputs have one owner, 1XPTg…
Yes
2
“Consolidation”
The address that got paid, 17SkEw…, is theirs too
No, it was a payment to jercos
3
Follow the money
The 5,777 and the 4,223 the payment split into are still theirs
No, because of step 2
4
Common input
On Jul 7, 2010, the 20 coins that go in together are theirs too: 11,022 BTC
No, because of step 2
5
“Consolidation”
The app tags that one CONS too, so the address it pays would be theirs as well
No, because of step 2
THE RESULT
The one who paid and the one who got paid end up as the same owner. jercos’s coins are attributed to Laszlo, along with everything jercos did with them afterwards. They were two different people.
THE RULE THAT DOES HOLD
“Some linking is still unavoidable with multi-input transactions, which necessarily reveal that their inputs were owned by the same owner.” Satoshi Nakamoto, Bitcoin whitepaper, 2008. It is about the inputs, and the output is left out.
All five steps use reasonable rules, and no rule of the chain corrects the mistake. A fact from outside corrects it, the report on the forum.
13
In dollars of the time
10,000 bitcoin, 41 dollars
US$ 41what the 10,000 BTC were worth on May 18, 2010, according to a forum user. About 0.4 cents each
US$ 25what the two pizzas cost, according to Laszlo, “maybe 30 if you give the guy a nice tip”
US$ 400what they were worth when jercos spent them, as he said in 2015
WHAT DOES NOT MATCH
jercos remembers ordering from Domino’s, but the photos show Papa John’s. It cannot be known, and it changes nothing of what the chain says.
TO THIS DAY
The address that got paid has received 50 small transfers since 2015, 38 of them in 2026, and none has been spent. As with the genesis, they are usually read as tributes. The chain only shows the transfers.
There are no prices on the chain. All three come from the forum (May and June 2010) and from the interview with jercos (2015).
14
Read with care
What the chain says, and doesn’t
Claim
Where it comes from
A transaction gathers 131 coins from one address and pays 10,000 BTC to another
Chain
That transaction is the pizza payment
Outside: the 2015 interview and the Wiki. The chain is consistent
Laszlo Hanyecz paid and jercos got paid
Outside: Laszlo on the forum and the interview
6,100 BTC of the payment come from 122 coinbases, two hops back
Chain
Laszlo mined those coinbases
Inference, consistent with what he said
Who sent the 111 coins of 0.01 and why
Not known
The two parts of the 10,000 are spent together on Jul 7, 2010
Chain
Whose wallet that was
Not known
It is a consolidation, as Satsumap says
False: it was a payment to someone else
The 10,000 BTC were worth 41 dollars
Outside: the forum, May 2010
What the chain says, anyone can check, with the TXIDs on the next sheet.
Each TXID and address opens Satsumap with one click, and next to it is the link to mempool.space. You can also copy them and paste them into either search box.
Sources outside the chain: Laszlo Hanyecz, “Pizza for bitcoins?”, Bitcoin Talk (2010) · interview with jercos, Bitcoin Who’s Who (2015) · Bitcoin Wiki.
