liqudity pool, people lock up Hive and HBD under the promise HBD it's worth 1$. 10% interest rate moves there.
If we have 10M HBD and in the pool are 5 Million HBD. It would need 10 Million Hive for current prices.
There could be additional to the 10% trading fee reward.
The point would be, Like fiat money, it would become trust-backed. As long someone trades for 1$, it's worth 1$.
If you can convert cheaper and buy back, you can make a profit.
If the pool would become deep enough, it would make HBD super stable. Important for that would be delete the 5% fee.