Whoever brought the value of SBDs this far up will have an increasingly difficult time keeping it there now that STEEM is more valuable and more SBDs are printed as a result.

I am personally a bit unsure. I think 2018 will be a great year for STEEM and that in the long term STEEM at 5$ will still be cheap. At the same time, things have gone up so quickly that it is also a good time to take some profits short term. So I am currently using 50% of my SBDs earnings to buy STEEM and Power Up. And 50% I sell. So in practice, it means that 75% goes into STEEM.