The blockchain considers an SBD to be worth $1 worth of STEEM. But the markets have decided to trade SBD for much higher. But the blockchain does not look at the markets when it comes to SBD so it thinks it's only worth $1 and that what it shows.

Now the true value of an SBD is, in fact, $1 worth of STEEM and nobody has found a good explanation yet why it's trading higher at the moment.

As soon as you turn those SBD into STEEM the blockchain will show the correct value.

Next time I would not by SBD but STEEM straight away if you want to buy STEEM.