yes they are insured but up to $250k only per account.
Our custodial accounts have been established in a manner to make pass-through FDIC insurance available up to the per-depositor coverage limit then in place (currently $250,000 per individual).
So make sure your deposit doesn't exceed their insurance limit. It’s always wise not to keep your Bitcoin on an exchange since you don’t own the keys. Exchanges are mostly for trading purposes only, so as long as your capital isn’t too large, your funds should be safe as long as they don't exceed the coverage ceiling.
This insurance only covers cash balances deposited through bank transfers, debit cards, PayPal, etc. For crypto, according to their TOS, it's covered by crime insurance, though they haven't specified the exact coverage amount. If a substantial amount is lost, like in the billions, only a portion might be covered. But since it's a regulated exchange, they could seek government support to track any hacked funds. I’m sure they don't keep all their funds in a single cold wallet either—they likely have risk management strategies and solid internal controls to minimize risks. Of course, no exchange is hack-proof.
As for Binance, the amount that was hacked before was manageable, given their massive daily trading volume. Currently, they're number 1 on the list (
https://coinmarketcap.com/rankings/exchanges/) with $8 billion in volume, so they might earn a minimum of $5 million per day just from trading fees. The SAFU funds (a percent of their revenue) are internal funds specifically set aside for these situations; I’m not sure if Coinbase has a similar setup.