Let's say you convert 1000 HIVE right now. You get 209 HBD. You sell HBD and buy HIVE.
After 3 days, you get the rest of your HIVE. If the price was higher, you get more HIVE. If the price stays stable, you pay exactly $1.05 per HBD.

So either way, you profit. i.e. you gain more HIVE than you had