And here is where the "Magic" of the system comes in. It is already pegged, but not an imposed peg by a central authority.

The peg is based on the natural market forces. 
If It gets too high, more SBD is printed, increasing supply. When there is more SBD on the market than money willing to buy It, the price Will fall naturally.

If the price is too low, direct conversion to steem, wich Destroy the sbd become avaiable, therefore reducing supply. And people will do that, because It Will be profitable.

And scarcity doents play a role, because on the long run, there Will always be more SBD being printed. 

Hodl Steem might be a good idea, because of its function.

But hodl SBD ... Bad Idea. 

And dont mind the trade speculators. If there is price volatility, they Will be there, and they Will make the price move on short term.

But long term, It is other gears that move the market.