Granted, I don't have any insider information on how Coinbase actually deal with things, I'm only judging things by the public information they put out themselves. Also, I don't keep any funds at Coinbase myself, for whatever it's worth.
But this is what Coinbase themselves say:
> There can’t be a “run on the bank” at Coinbase. As you can review in our publicly filed, audited financial statements, we hold customer assets 1:1. Any institutional lending activity at Coinbase is at the discretion of the customer and backed by collateral. We have no gating for client loan recalls or withdrawals.
This is from https://www.coinbase.com/blog/our-approach-to-transparency-r...