At 4:24pm New York time on Thursday, one of Binance's hot wallets (the online wallets an exchange uses for everyday withdrawals) sent 167,464 ether, 1.6 billion USDT and 61 other tokens to an address created hours earlier. Changpeng Zhao, who co-founded Binance and no longer runs it, said within the hour that it "does look like a hack."

By Friday morning Binance put the damage at about $6.3 billion, and Chainalysis, the blockchain forensics firm, at about $6.4 billion. Tether says it froze more than $1.5 billion of the stolen money and Circle more than $800 million. With smaller freezes by the Arbitrum security council and other issuers, Binance counts about $3 billion that cannot move.

Binance first traced the attack to a compromised laptop belonging to one of its engineers, has since found further points of breach, and says it has seen no sign of a leaked private key. TRM Labs, another forensics firm, says with high confidence that the attackers were TraderTraitor, a North Korean hacking group. Binance has not named anyone. It says it will cover every user loss from its emergency fund and its own money. Deposits are working again, and Binance says it is on track to restart withdrawals within two days.

Traders sold before any of that was known. Bitcoin went from $81,138 at Thursday's reading to $76,880 at Friday's (00:44 UTC), down 5.2% and its first reading under $80,000 since September 18. Ether fell 6.3% to $2,207 and solana 8.4% to $93. Coinglass counts $628 million of leveraged bets wiped out in a single hour, 97% of them bets that prices would rise. On Uniswap, hundreds of ether changed hands at about 20% above the reference price while people paid up to get out of anything that touched Binance.

DefiLlama still counts about $135 billion in Binance's reserves against a $6.3 billion hole, and the exchange kept its promise to users on Thursday. An exchange balance is still an IOU from a company, backed by that promise and whatever the company holds in reserve. Coins in a wallet you control depend on neither, and after a night like Thursday's that is worth remembering before you decide where to keep yours.

Intercontinental Exchange owns the New York Stock Exchange. It is taking a minority stake in trade.xyz, the biggest builder of markets on Hyperliquid, and Stan Druckenmiller is investing alongside it.

The plan is a US venue called ICE[XYZ] with its own exchange and clearing house built on Hyperliquid. It would list perpetual futures (bets on a price with no expiry date) on stocks, indexes, commodities, currencies and crypto for identity-checked traders. It needs CFTC approval first, and neither side gave a launch date or a price for the stake. trade.xyz says its existing Hyperliquid markets have done more than $650 billion of volume in just over a year and will keep running.

HYPE rose more than 10% on a day everything else fell. If the regulator says yes, the perpetual futures that live on offshore crypto exchanges today would trade on a US-regulated venue with the NYSE's owner behind it.

Polymarket stopped all new trading on Thursday, minutes after a trader reported $800,000 drained from his account. The company put its exchange into cancel-only mode (you could cancel orders but not place them), blamed a third-party provider and said losses came to about $2.65 million. Trading has resumed and it says affected users were made whole.

It was Polymarket's second bad headline this week. Bloomberg reported that Polymarket is investigating suspicious bets on Israel's election, where some accounts together cashed out more than $100,000. Senators Elizabeth Warren and John Curtis have written to Polymarket and Kalshi, the other big event-betting venue, asking how they stop insider trading on election bets, with answers due by November 3, the day of the midterms.

For anyone with money on a midterm market, the venue has to keep your balance safe and keep the odds clean, and this week it was asked about both.