Some believe SBD's are not burned on CONVERSION. Trading can be very delicate. The best resolution in my opinion is to buy STEEM with $SBD and then trade the STEEM for whatever crypto you want. I just bout 473 Steem for $69 SBD. The Steem is trading now at $1.85 US. You do the math. I'm not advising. I'm not a professional financial advisor. Just relating to you an anomaly I uncovered re $SBD.