Maybe i got this wrong. As i know it takes 7 days to recieve your SBD.
I guess you are getting an amount of SBD that is equalent to $1 on bittrex.
Following this, you would get 2 SBD tokens if the price is sitting at $0.5
Please correct me iam genuinely interested in finnaly grasping this.
It's not pegged to the outside markets. If the price on bittrex is 0.5$ for 1 SBD you will still receive only 1 steem dollar. It's your decision to then sell it on the market for 0.5$ or not