If the price is below a dollar and it has received HBD, rather than sending it right back, it will convert it into HIVE. Depending on what happens 3.5 days later when the conversion finishes, it might be used to buy HBD, or that HIVE might just get sent back to DHF (which automatically converts it back to HBD). In the latter case it ends up being the same amount of HBD as before the conversion. In the former case it will depend on market conditions but should usually end up with more.