5 years of having no interest and therefore no particular reason to buy it or hold it. Mostly its been converted back down to HIVE (which in turn has likely resulted in more selling pressure on HIVE and a lower price)
Anyway, after the next hard fork it will be possible to convert HIVE into HBD. So as much as there is demand for can be created.
RE: Why I set my witness HBD interest rate parameter to 7%