He called the flaw a sign of deeper problems in how hardware wallets get tested across the industry. Hardware wallets? The argument is pretty straightforward: if those standards exist and other industries use them, there’s no good reason hardware wallets should be exempt. Hardware wallets are supposed to be the safe option — the alternative to leaving Bitcoin on an exchange and hoping the platform doesn’t blow up. Frequently Asked Questions What caused the Coldcard security flaw that led to $90 million in Bitcoin losses?