Coldcard Bitcoin Wallet Hack Leaves Over $100 Million in Losses

A massive hack of Coldcard Bitcoin wallets has left over $100 million in losses. The breach was caused by a firmware flaw introduced in March 2021, which allowed attackers to pre-compute candidate seeds and sweep single-signature wallets. This weakness made seed phrases easier to guess offline.

The first major sweep occurred on July 30, 2026, draining over 1,000 BTC from more than 1,200 addresses in under an hour. Two further waves followed, targeting remaining vulnerable balances.

Ripple CTO Emeritus David Schwartz (@JoelKatz) weighed in on the incident, drawing comparisons to historic TradFi failures such as MF Global in 2011. He noted that insurance availability in traditional finance does not currently extend to self-custody crypto losses.