In 2013, an Argentinian researcher named Sergio Demian Lerner published an analysis claiming that a single mining entity had produced roughly 22% of all blocks in Bitcoin's first year, accumulating somewhere between 750,000 and 1,100,000 BTC. The fingerprint, he argued, was hidden in the coinbase scriptSig of every block that single miner produced. Almost certainly Satoshi Nakamoto. Almost certainly never spent.
The pattern, called Patoshi after the analysis, lives on chain in plain sight. Anyone with a node and an afternoon can verify it.
What's a coinbase scriptSig?
A coinbase transaction is the special tx that mints the block subsidy. Its single
"input" doesn't reference a prior output (there's no prior tx for the first transaction
in a block); instead, the input has a scriptSig field that miners can
fill with arbitrary bytes. Modern miners stuff in pool tags and ASCII messages.
Early miners were less self-aware; they often left the bytes in their default form,
which exposed implementation details.
Pull the genesis block's coinbase to see this in action:
The full scriptSig: 04ffff001d0104455468652054696d6573.... The
leading bytes are header (height encoding, in pre-BIP34 days), then the
actual data payload.
What Lerner found
Lerner pulled the coinbase scriptSig of every block from 1 to ~50,000 and looked at one specific field: the ExtraNonce. The ExtraNonce is a counter the miner increments when the regular nonce range is exhausted; it's part of the data the SHA256 hash function operates on.
The reference Bitcoin Core software increments ExtraNonce in a specific way. But Lerner noticed that about 22% of all early blocks had ExtraNonce values drawn from a dramatically different distribution. The pattern: ExtraNonce stayed very small (often single digits), implying that single miner found blocks before needing to push ExtraNonce up. They had so much hashpower (relative to the network) that the regular nonce range was almost always sufficient.
The other 78% of blocks showed normal incremented ExtraNonces, suggesting many different miners with normal hashpower distributions.
See it for yourself
Pull a few early blocks and look at the coinbase scriptSig bytes. The ExtraNonce sits in a predictable position. Block 1:
Now block 100:
And block 50,000, well after the Patoshi pattern stops:
If you fetch each block at verbose=2 and decode the coinbase
scriptSigs, you can manually trace the ExtraNonce pattern Lerner used.
The original analysis (and its modern updates) are public, but the data they
rely on is right there on chain.
The Patoshi pattern stops
Around block 54,000, the pattern abruptly disappears. After that point, no blocks show the small-ExtraNonce signature. The mainstream interpretation: Satoshi stopped mining around late 2010, possibly to avoid a 51% problem as more miners came online, possibly because they were ready to step away from active maintenance.
A few months later, in April 2011, Satoshi sent his last public messages and disappeared. The roughly 1.1 million BTC mined under the Patoshi fingerprint have not moved in 16 years. Today they're worth tens of billions of dollars.
Why it matters
The Patoshi analysis is the closest thing we have to an objective measurement of Satoshi's holdings. It's not perfect (other miners may have shared the same early Bitcoin Core version and produced similar patterns), but the cluster is dramatically isolated from the rest of the network's behavior. Most analysts accept that the patterns identify a single dominant early miner, and that miner is overwhelmingly likely to be Satoshi.
These coins represent a structural supply overhang: roughly 5% of the eventual 21M cap, sitting in addresses with no known private-key holder and no movement for over a decade. Every Bitcoin holder is implicitly betting that they'll never move, or that the market can absorb them if they do.
You can check on Satoshi's coins any time by querying balances at the addresses publicly attributed to the Patoshi cluster. They've been monitored continuously by analysts for years. So far, nothing.
Read more: The Genesis Block, The Halvings, or SegWit Activation.