A hacker drained most of the Bitcoin backing Liquid, Bitcoin's oldest side chain — bad for the institutions using it, but harmless to Bitcoin itself.

• Someone exploited a bug and walked off with $320 million in Bitcoin, leaving 95% of Liquid's reserves empty in minutes.
• The bug was simple: the system remembered old approved transactions and waved through copies without rechecking the details.
• The hackers found it because Blockstream posted the fix to a public code repository before every computer on the network had installed it.
• They now call themselves "white hats" and are negotiating a bounty, because $320 million in traced Bitcoin is nearly impossible to spend.
• The pain lands on trading firms and exchanges, not regular holders, and the companies involved are big enough to absorb it.

Outlook: Most of the money is likely to come back once a payoff deal is signed, leaving a black eye for Bitcoin's side-chain layer rather than for Bitcoin.