For years, hardware wallets have been promoted as one of the safest ways to store cryptocurrency. The idea is simple: keep your private keys offline, away from hackers, and your assets remain secure. The latest exploit involving the Bitcoin hardware wallet Coldcard is challenging that belief. Security researchers say attackers exploited a vulnerability affecting Coldcard wallets, with blockchain analysis now estimating that roughly $70 million worth of Bitcoin was stolen from more than 1,100 wallets . The incident has become one of the biggest hardware wallet security events in recent years, raising fresh questions about how investors should think about self-custody. A Reminder That No System Is Perfect The exploit doesn't mean hardware wallets are unsafe. It does, however, show that no storage method is completely immune to risk. Hardware wallets are designed to protect users from online attacks, malware and exchange failures. But like any piece of technology, they stil...