Previously, BitMEX has used multi-signature, once per day withdrawals to maximise our security. From today, we have added hourly withdrawals for small amounts of BTC , falling back to our "once per day" BTC withdrawal process for larger withdrawals. For the finer details of our new withdrawal process, read our blog. Alternatively, you can learn more about our security practices here. As always, if you have any questions you can contact Support.