BITCOIN TO STEEM TRANSFER --- SEEMS LESS IN USD VALUE?????

Can someone please explain to me,
why when I transfer $50 USD worth of btc into Steem Power (in this instance)
only translates to about $23 USD worth?

Previously I had about $17 USD worth before the above transfer.

Does 15 Steem Power translate to $50 USD? why would it not indicate so in the value worth?
My previous Steem input I am finding has been roughly halved....

I realize that I am a bit late to the party, but Please someone explain this to me...