Right. When steem is cheaper relative to SBD then it's a good time to convert.

For example. Let's say steem is worth $10. At the current value of 1SBD you can buy 0.819 steem. But then let's say steem is worth $1. Then you can buy 8.19 steem at the current price of SBD.

Ideally you want to buy steem when it is cheaper than the price of SBD.