Bitcoin at risk: How Coldcard rattled the entire crypto industry

​Losses linked to the Coldcard hardware wallet vulnerability are now estimated at more than $100 million in Bitcoin. The incident has revived debate over one of crypto's oldest security principles: keeping long-term holdings off exchanges and under your own control. But what does secure Bitcoin storage actually look like?

A growing security incident

Coldcard manufacturer Coinkite recently disclosed a flaw affecting vulnerable firmware released between March 2021 and July 2025. According to the company, affected devices could generate recovery seeds with significantly reduced entropy because of an error in the wallet's random number generation. The issue spans several generations of devices, including Coldcard Mk2, Mk3, Mk4, Mk5 and Coldcard Q.

The company has released patched firmware, but wallets created with vulnerable software require more than an update. Coinkite advises affected users to generate a new recovery seed and migrate their funds.

According to Galaxy Research, attackers have now stolen approximately 1,800 BTC, worth about $114 million, across at least four coordinated attack waves targeting affected wallets. Researchers say additional compromised addresses continue to be identified, suggesting the full scale of the incident is still unfolding.

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The scale of the incident surprised many Bitcoin users because Coldcard has long been regarded as one of the industry's most security-focused hardware wallets. Designed exclusively for Bitcoin, it became particularly popular among experienced users thanks to features such as air-gapped signing, open-source firmware and a strong emphasis on minimizing attack surfaces.

Confidence in self-custody

The exploit also affected market sentiment. Bitcoin price fell by more than $1,000 over the past day as news of the vulnerability spread, although the selloff coincided with broader market pressures. Some commentators linked the decline to growing concerns about hardware wallet security, while blockchain analytics firm Santiment reported rising anxiety across the market after funds began moving from wallets that had remained dormant for years.

Whether the vulnerability materially influenced Bitcoin's price is difficult to determine. Crypto markets respond to many factors simultaneously, and security incidents often unfold alongside broader macroeconomic developments.

Even so, the reaction highlights how much confidence Bitcoin holders place in hardware wallets as the foundation of self-custody. That confidence developed for a reason.

Why hardware wallets became the standard

Bitcoin's original promise was that users could become their own bank. The trade-off was equally clear: there would be no institution to reset a password, reverse an unauthorized transaction or recover lost funds.

Over time, the industry settled on a simple approach. Exchanges offered convenience but required users to trust a third party with their assets. High-profile failures such as Mt. Gox and FTX reinforced the principle that investors should control their own private keys rather than rely on centralized custodians.

Hardware wallets became the preferred solution because they keep private keys offline and under the owner's control. For years, one recommendation came to dominate Bitcoin security discussions: buy Bitcoin on an exchange, then move it into cold storage.

The Coldcard vulnerability does not necessarily overturn that advice. It does, however, remind users that self-custody also depends on the security of the hardware and software used to generate and protect private keys.

Every storage method has trade-offs

The latest incident highlights a broader reality. Every method of storing Bitcoin protects against certain risks while exposing users to others. The most appropriate approach often depends on the size of the holding, how frequently funds need to be accessed and which threats an investor is trying to reduce.

Firmware vulnerabilities remain relatively uncommon. Security researchers continue to identify phishing attacks, fake wallet applications, social engineering and compromised recovery phrases as far more common causes of cryptocurrency theft.

The Coldcard incident does not show that hardware wallets are fundamentally unsafe. It does, however, illustrate why Bitcoin security has always been about understanding different types of risk rather than relying on a single product.

Security is becoming more layered

As the value of digital assets has grown, many long-term Bitcoin holders have adopted more sophisticated approaches to security.

Large investors increasingly distribute funds across multiple wallets, keep backups in separate locations or use multisignature arrangements requiring several independent keys before transactions can be authorized. Many institutional custodians rely on similar principles to reduce dependence on any single device or recovery seed.

Most retail investors do not need institutional-grade custody practices, but buying hardware wallets directly from manufacturers, keeping firmware up to date and protecting recovery phrases offline remain among the most effective ways to reduce risk.

The Coldcard incident is also a reminder that self-custody is not something users establish once and forget. Like any security system, it requires ongoing maintenance as software, devices and threats continue to evolve.

The next chapter in self-custody

For years, the conversation around Bitcoin storage focused on a simple recommendation: move your coins off exchanges and into cold storage. The Coldcard incident does not necessarily challenge that advice, but it does show that secure self-custody depends on more than choosing the right device. It also depends on how that device is used, maintained and updated over time.

Bitcoin was designed to reduce the need to trust financial intermediaries. As the ecosystem matures, the discussion may gradually shift away from finding a single "safest" storage method and toward understanding the trade-offs behind every layer of security.