It sends that HIVE back to the Hive DAO, where the HIVE is being converted to HBD

HIVE transfers are converted instantly. Only the existing HIVE balance is converted slowly.

It might be nice to see the HIVE transfers chart in HBD (how much HDB is added to the DAO by HIVE transfers, which are converted instantly). This would make it clear how the stabilizer is sending back a lot more HBD than it is receiving. But it might be hard to do since you would need the conversion price at the time. I don't think there is a vop recorded for that, but there probably should be. @howo