A bitcoin wallet dormant since 2013 moved $31 million

Since July 30, attackers have drained thousands of BTC from Coldcard-generated wallets, exploiting a flaw dating back to March 2021. According to researchers at Galaxy, total damage so far is about $130 million in BTC.

Over the weekend, some analysts pointed to increased inflows of BTC onto exchanges as the hack dented confidence in self-custody safety.

The 500 BTC isn’t an isolated case

On-chain data from CryptoQuant tracking the so-called spent output age bands, an indicator which groups all bitcoin moved on a given day by how long each coin had sat dormant before being spent, reveals a clear spike in old-coin movement around the same window.

Coins that had been dormant for 10 years or longer saw roughly 935 BTC move on Aug. 3, the largest single-day total since March 20. Separately, coins dormant for five to seven years saw a much larger spike, with roughly 6,388 BTC moving on July 31.

Old coins move for all kinds of reasons, such as estate transfers, exchange consolidations, custodial migrations that have nothing to do with any single hack.

But the clustering of large, long-dormant movements in the days immediately following the Coldcard incident gives the impression of holders proactively migrating funds for security reasons.