Usually when some exchanges find out that they're are running short of funds they usually claim to be undergoing a maintenance or major update. On a few occasions, the honest exchanges usually come back bigger and better while other find it as an avenue to run away with traders funds without any trace at all. Though I'm not criticizing any exchange, I have actually never come across an exchange that came back from its acclaimed maintenance. After knowing all that, I'll be talking about HashKey Pro.
HashKey Pro Exchange is just like alot of exchanges; it allows for the easy transaction between buyers and sellers of cryptocurrencies. I haven't used this exchange before so I can't give a full account concerning my trading experience here. But since the founder claims to be undergoing maintenance without any known date of relaunch, I'll advise both new and old traders to stay away from this exchange.