Just remember that there's only one fundamental change in the hard fork that should have an instantaneous effect on price, and that will come into effect in one week: the change to a 13-week power down instead of a 104-week. In one week, the effective liquid supply of Steem will likely increase instantaneously, which may have the effect of decreasing the price.
The decrease in inflation from the hard fork should increase the price long-term, but IMO there's nothing about the inflation change that should cause the price to rise 68% in one day.