The @hitbtc account has 29.742 steem, 12.478 SP and 10.579 SBD in their wallet. Unless if they are using a different account a 5 digit volume doesn't seem real to me.
EDIT: Also their order book in the SBD/BTC pair has a depth of 111,976 on the ask side while the SBD/USDT pair has 3667 and the one for SBD/ETH has 1036. Which account is holding that amount of SBD? If they do have does amounts in their wallet I will retract my statement.
RE: Why Is SBD Getting Dumped Like This?