Freezes come in innocent and terminal varieties, and they look identical from outside on day one. A chain upgrade or a hot-wallet rotation pauses withdrawals for hours; insolvency pauses them permanently, usually with a message about protecting all customers.
Watch the shape of the announcement. Narrow, specific, time-bounded and asset-specific pauses are routine. A blanket halt across all assets, especially one that follows heavy outflows, an odd depeg in a venue's own token, or public disputes about reserves, has historically preceded bankruptcy filings.
Because you cannot tell them apart in the moment, the decision has to be made before it happens. Size your balance on any venue as though a freeze is possible, and be aware that queueing to withdraw during panic is a race you may simply lose.
Related: exchange-insolvency-risk, cex, proof-of-reserves, self-custody