The Coldcard bug was not found by a hacker. It was found by someone reading code that had been public for years.

Insiders. Researchers. Anyone with time and motivation.

Closed source wallets are not safer from this. They are just harder to check - which means bugs live longer and hurt harder.

The scariest part of the Coldcard story: the code was open, and it STILL took years to find the bug. Imagine how long it takes with closed code.

Never closed. Never blind. Blockstream Jade is open source for a reason.

The more eyes, the faster the bugs die.

Coupon LOVEISBITCOIN.
Link: loveisbitcoin.com/blockstream