SBD will only ever be redeemable for $1 USD worth of Steem - I think people buying it at double the price are willing to lose up to half the $ value in order to lock in massive their massive $ gains on bitcoin without having to go into fiat.

Once that becomes less appealing again and demand drops then suddenly we'll have a race to take any premium/free money left on the table.

Buy SBD < $1 , sell SBD > $1.50 and keep the bitcorns to buy Steem on dips imo thats what I'm doing with extra SBD these days. It's hard to be dissapointed selling post rewards for double what they're displayed as.