15% APR is only paid on HBD in savings which presumably isn't all (though I have no idea what the percentage is).

I seem to recall a while ago that there was some discussion about introducing a certificate of deposit style mechanism to HBD whereby you would get a higher interest rate if you locked it up longer. I guess nothing ever came of that. Personally, I see no reason to hold HBD if it drops below 10% but I'm willing to lock it up longer to get higher rates.

I'm not sure what the solution for the DHF is. Maybe there should be a maximum distribution rate and once that rate is surpassed, nothing else is funded.