The Steem blockchain always assumes that 1 SBD is worth $1 when doing the conversion process. Therefore, you can receive a 18.6% bonus IF the conversion rate remains constant.
The conversion process takes 3.5 days to execute and if the value of 1 SBD spikes over $1 your bonus could become a penalty. Therefore, execute the conversion at your own risk and watch the broader crypto markets .
I cover the STEEM token and where the SBD is going in my Daily Investor Report. The entire crypto market is down and appears like it will remain down for the next week. Tune in and follow to keep up with the daily price movements of STEEM.