If your withdrawal was under $50,000, your transaction will remain on "Pending" until it is confirmed by the blockchain network of your coin. We can't influence the speed of the verification process, if there is a lot of traffic at that moment it will take some time for the transaction to get approved. As soon as it is confirmed by the network the coins will be visible on your wallet.
If your withdrawal was over $50,000 it will remain on "Pending" until we approve it. We always do our best to approve large withdrawals within 24 hours, and we will contact you if there are any issues preventing us from approving it so we can resolve those issues as fast as possible.