Nearly $114 million in bitcoin vanished from Coldcard wallets across four separate sweeps. The market barely flinched. Bitcoin climbed past $64,100 overnight, up 2 percent on the day, while blockchain analysts continued tracking the damage from what started as a single event five days earlier and morphed into something far grimmer.
The disconnect between the scale of the loss and the absence of panic selling is what matters here. This was not a phishing scam, not malware, not someone stealing a hardware wallet from your desk. The vulnerability was baked into the firmware at the moment each wallet generated its recovery seed, sitting dormant for over five years before anyone noticed.
Coldcard's seed generation relied on a function that pulled randomness from the hardware. The codebase contained two versions of that same function, one properly hardened for the STM32 chip and one inherited from MicroPython as a fallback. A preprocessor guard checked whether a build setting existed but never verified its value. The result was the system compiling against the weak software version in silence, producing recovery phrases that looked perfectly valid. They passed all the standard randomness tests because they were random enough to fool automated checks. An attacker who could determine the device UID, timer state, and prior call history could reproduce the seed offline without ever touching the hardware. The flaw shipped in firmware 4.0.0 on March 1, 2021.
Coinkite and Chainalysis first reported roughly 594 bitcoin, about $38 million, drained from around 500 wallets in a 25-minute window on July 31. Galaxy Research then identified a separate, larger sweep touching 1,196 addresses holding 1,082.65 bitcoin, worth roughly $70.2 million. The figures shifted daily as different analysts mapped different transaction clusters. By Monday, a fourth drain had been confirmed.
The real puzzle is not the theft itself but why Bitcoin's price ignored it. Market participants appear to be treating this as a Coldcard-specific catastrophe rather than a systemic flaw in bitcoin's security model. The distinction matters. Coldcard is one wallet manufacturer among many. The underlying bitcoin network and the cryptography protecting it remained untouched. That separation may be exactly why traders kept buying dips instead of heading for the exits.
This article is informational only and should not be construed as financial advice. Always conduct your own research before making investment decisions.
