Chainalysis is a company valued at over $8 billion. Their entire business model is built on one thing: tracing Bitcoin transactions and selling that data to governments, law enforcement agencies, banks and crypto exchanges.

They are watching every Bitcoin transaction ever made. Including yours.

Understanding how they work is the first step to protecting yourself. Here's exactly what they do.

The Blockchain is Public — Forever

The foundation of Chainalysis's power is simple: the Bitcoin blockchain is a permanent, public record of every transaction ever made. Every address, every amount, every timestamp — all publicly readable by anyone in the world, forever.

Chainalysis didn't create this surveillance capability. They just built the most sophisticated tools to exploit it.

CIOH — The Core Heuristic

The most powerful technique Chainalysis uses is called CIOH — Common Input Ownership Heuristic.

When you send Bitcoin, your wallet often combines multiple inputs from different addresses into a single transaction. The CIOH assumption is simple: if multiple addresses are used as inputs in the same transaction, they are controlled by the same person.

This allows Chainalysis to cluster thousands of addresses together under a single identity profile. One careless transaction can link your entire transaction history.

Real example: You have BTC at three different addresses. You make a payment that combines all three as inputs. Chainalysis now knows all three addresses belong to you — and can link every transaction those addresses have ever made.

Exchange Data — The Identity Link

Clustering addresses is powerful, but it only tells Chainalysis that a group of addresses belongs to the same person. To find out who that person is, they need an identity anchor.

That anchor comes from KYC exchanges.

When you buy Bitcoin on Coinbase, Binance or any regulated exchange, you provide your name, address, ID and sometimes more. The exchange then records which address you withdrew your Bitcoin to.

Chainalysis buys or subpoenas this data. Now they know: this cluster of addresses belongs to the person with passport number X, living at address Y.

Change Address Tracking

When you send Bitcoin, you rarely spend exactly the right amount. The remainder — called the "change" — goes back to a new address in your wallet. Chainalysis's algorithms identify these change addresses and add them to your cluster automatically.

Transaction Graph Analysis

By mapping the flow of funds between addresses over time, Chainalysis builds a complete picture of your financial life:

Who Buys This Data?

The uncomfortable truth: Every time you transact in Bitcoin without taking privacy precautions, you are potentially adding data to Chainalysis's database that could be used against you at any point in the future.

See What They See — For Free

Wizardo.tools lets you visualize exactly how Chainalysis-style clustering works on any Bitcoin address. Enter any address and see the cluster map, privacy exposure score and how many hops away you are from a KYC exchange.

Knowledge is protection. Once you understand how tracking works, you can take steps to prevent it — fresh addresses, coin control, CoinJoin, and swapping to Monero for true privacy.