Like taraskp said, there are a few times that SBD bought a lot of steem, and thee are times like now when it does not. And like everitt told me, if you want to make money on steem, you need to have SP to vote, the more the better. Right now you SBD might only buy you say 2 steem, in a month it might still only buy you two steem, or it might buy you 5 steem, not even god knows how much it will buy then. But during that month that 2 steem is working for you, not sitting idle earning nothing, growing nothing. If you are going to hold it, I don't know how often they pay interest in the saving account part but maybe look into that, Of course if you need funds right away, I think it takes 3 days to with draw from your savings account.