Some interesting thoughts there... one of the things I've noticed is that the price of SBD seems somewhat correlated with the VOLUME of Steem being traded on the exchanges. As the Steem volume increases, so does the SBD price. My guess would be the relationship there is that when the markets are hot, there are more newbie speculators playing... and they may not realize that Steem Dollars aren't "just another alt coin" and inadvertently help run up the price. I realize that's pretty unscientific... just a hunch.