While I strongly suspect there are elements within that group that are profiting from the pumps in SBD and HBD (more from SBD, for obvious reasons), I believe they are mostly profiting from the arbitrage opportunities between the other markets and upbit (which anyone who trades on upbit can do, I'm sure they're not alone).
This is imo the most plausible hipotesis, as it hasn't sense if their purpose it's to attack Hive, to pump first Hive and then HBD. Actions that actually benefit more that harms this blockchain. Anyways is good to follow this movements closely.