If by "current market value" you mean this instant, then yes it is a bit overvalued, but mostly it just isn't that stable. On several occasions in the past week and even in the past 24 hours, the price has dropped to $1 and the stabilizer has stopped selling (and has even done a tiny bit of buying).

Realistically we can't make changes like the interest rate on an instantaneous basis and need to make a longer term assessment.

Also, when HBD is overvalued I don't believe the interest rate serves as much of an incentive to hold it (of course it does somewhat) for the simple reason that anyone buying or holding at more than a 5-10% premium is clearly speculating, and stands to make or lose a lot more than the interest. In that case, paying it is probably a little wasteful but likely not all that effective or harmful in terms of price action. It's more effective as an incentive to hold when the price is at or near $1 (interest serves as upside and downside is limited).