The fact that they’re letting you deposit double what you can withdraw means they don’t have enough Monero on their books to make it up for everybody. Otherwise, the deposit and withdraw amounts would be equal.

That conclusion does not follow from the limits alone. Deposit and withdrawal limits are operational policies, not a statement of the exchange’s Monero reserves. They can be asymmetric for many reasons, including compliance requirements, fraud prevention, or liquidity management.

A lower withdrawal limit might justify asking questions, but it is not evidence by itself that the platform is running a fractional-reserve scheme. To establish that, you would need information about its liabilities, on-chain reserves, withdrawal delays, failed withdrawals, or other evidence of a shortfall.